vendex and Osteoarthritis--Knee

Topics: Bone Malalignment; Humans; Joint Deformities, Acquired; Knee Joint; Osteoarthritis, Knee; Stress, Mechanical; Torque

Muscle weakness is characteristic of knee osteoarthritis. Muscle steadiness may be an important adjunct to knee muscle strength in improving physical function in knee osteoarthritis. However, the role of muscle steadiness is uncertain.. To determine the associations of knee extensor muscle steadiness with maximal voluntary torque and physical function in patients with knee osteoarthritis.. Baseline data from 177 patients in a randomized clinical trial were used. Isokinetic knee extension torque was processed into maximal voluntary torque [Nm]. Muscle steadiness was expressed as the coefficient of variance [%] and as peak power frequency [Hz]. Physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, the Get-Up-and-Go and Stair-climb tests. Associations were determined using regression analyses and adjusted for confounders.. Lower muscle steadiness (i.e., higher coefficient of variance and peak power frequency) was associated with lower maximal voluntary torque (B = - 7.38, [-10.8, -3.95], R. Low muscle steadiness was weakly associated with low muscle strength and poorer self-reported physical function. Muscle steadiness and muscle strength seem to be different attributes of muscle function. There is no convincing evidence that muscle steadiness is an important adjunct in studying physical function in patients with knee osteoarthritis.

Topics: Humans; Knee; Knee Joint; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Torque

To determine whether knee stability, range of motion (ROM) and clinical scores differ between anterior-stabilized (AS) and posterior-stabilized (PS) total knee arthroplasty (TKA).. This prospective randomized controlled trial included 34 patients with severe bilateral knee osteoarthritis who underwent bilateral TKA between June 2010 and July 2011 using AS and PS designs of a single-implant system. AS TKA with ultracongruent inserts was performed in one knee and PS TKA with a cam-post mechanism was performed in the other knee in each patient. Clinical and radiological data from a mean follow-up period of 5 years, including ROM, clinical scores, peak knee torque determined by isokinetic test, knee joint laxity determined by Telos stress views, tourniquet time and subjects' preference were analyzed.. The mean postoperative knee flexion angle did not differ between groups until 1 year. Beginning 2 years postoperatively, the knee flexion angle decreased slightly in the AS group and was smaller than that in the PS group (p = 0.004). The mean Knee Society knee score was higher in the PS group than in the AS group after 2 years. The quadriceps strength did not differ between groups. The mean posterior laxity after TKA was 6-8 mm greater in the AS group than in the PS group. No radiological loosening was observed in either group. More subjects preferred PS knees to AS knees. However, this difference was not significant.. AS primary TKA was inferior to PS TKA in terms of posterior knee stability, postoperative knee flexion and clinical scores after 2 years.. Therapeutic study, Level 1.

Topics: Aged; Aged, 80 and over; Arthroplasty, Replacement, Knee; Female; Follow-Up Studies; Humans; Joint Instability; Knee Joint; Knee Prosthesis; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Postoperative Complications; Prospective Studies; Prosthesis Design; Quadriceps Muscle; Radiography; Range of Motion, Articular; Single-Blind Method; Torque

Resistance training (RT) can improve whole muscle strength without increasing muscle fiber size or contractility. Neural adaptations, which lead to greater neural activation of muscle, may mediate some of these improvements, particularly in older adults, where motor neuron denervation is common. The purpose of this study was to explore the relationship of neural adaptations, as reflected by neural cell adhesion molecule (NCAM) expression, to improvements in (1) whole muscle strength and (2) muscle fiber size following RT in older adults with knee osteoarthritis. We performed whole muscle strength measurements and immunohistochemical analysis of fiber size, type, and NCAM expression before and after a 14-week RT program.. RT increased whole-muscle strength as measured by 1-repetition maximum (1-RM) leg press (P = 0.01), leg extension (P = 0.03), and knee extensor peak torque (P = 0.050), but did not alter NCAM expression. Greater NCAM expression in myosin heavy chain (MHC) II fibers was associated with greater whole muscle strength gains (knee extensor peak torque r = 0.93; P < 0.01) and greater MHC II fiber size (r = 0.79; P < 0.01). Our results suggest that training-induced NCAM expression, and neural adaptations more generally, may be important for RT-induced morphological and functional improvements in older adults. Trial registration NCT01190046.

Topics: Adaptation, Physiological; Aged; Female; Humans; Knee; Knee Joint; Male; Middle Aged; Muscle Fibers, Skeletal; Muscle Strength; Muscle, Skeletal; Neural Cell Adhesion Molecules; Osteoarthritis, Knee; Resistance Training; Torque

To compare the "all-inside technique" for anterior cruciate ligament (ACL) reconstruction using a short, quadrupled semitendinosus tendon (ST4) autograft and suspensory cortical fixation on both the femoral and tibial side vs the "conventional technique" using a semitendinosus/gracilis (ST/G) autograft fixed with a suspensory device on the femoral side and with an interference screw on the tibial side, in terms of clinical and functional outcomes.. A total of 90 patients were enrolled, randomised into two groups, and prospectively followed. Group A comprised 45 patients treated with the all-inside technique and Group B included 45 patients treated with the conventional ACL technique (55 males, 35 females; mean age 28.7 ± 11.3 years). Patients completed the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Score (KOOS), and the Knee Society Score (KSS) preoperatively and at 2 years postoperatively. Anterior tibial translation measurement (KT-1000 arthrometer) and isokinetic testing of the operative vs non-operative limb were also conducted and the limb symmetry index (LSI) was determined.. At 24 months, the Lysholm, IKDC, KOOS, and KSS scores between the two groups were similar (n.s.). Anterior tibial translation between the operative and non-operative knee was also similar among the two groups (n.s.). Patients of Group A had significantly higher mean LSIs in terms of flexor peak torque (1.0 ± 0.1 vs 0.9 ± 0.1; p < 0.001), time-to-peak (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) and total work (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) at 180°/s, and significantly better mean LSI for isometric flexor/extensor ratio at 90° (1.1 ± 0.3 vs 0.8 ± 0.2; p < 0.001).. The all-inside ACL reconstruction with an ST4 autograft and cortical button fixation on both ends is a viable alternative to the conventional technique. It affords preservation of knee flexor strength, which is of advantage, especially when treating athletes with ACL injury.. I.

Topics: Adolescent; Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Female; Femur; Follow-Up Studies; Hamstring Tendons; Humans; Joint Instability; Knee; Lysholm Knee Score; Male; Muscle Strength; Osteoarthritis, Knee; Postoperative Complications; Prospective Studies; Tibia; Torque; Transplantation, Autologous; Young Adult

To determine the effects of neuromuscular electrical stimulation and low-level laser therapy on neuromuscular parameters and health status in elderly subjects with knee osteoarthritis.. A randomized evaluator-blinded clinical trial.. Forty-five elderly women with knee osteoarthritis.. Subjects were randomized into 1 of the following 3 intervention groups: electrical stimulation group (18-32 min pulsed current, stimulation frequency 80 Hz, pulse duration 400 μs, stimulation intensity 40% of maximal isometric voluntary contraction), laser group (dose 4-6 J per point, 6 points at the knee joint) or combined group (electrical stimulation plus laser therapy). The outcomes included muscle thickness and anatomical cross-sectional area (ultrasonography), knee extensors' electrical activity (electromyography), torque (dynamometry) and health status (Western Ontario and McMaster Universities Osteoarthritis Index). All groups underwent a 4-week control period (without intervention) followed by an 8-week intervention period.. Muscle thickness and anatomical cross-sectional area increased in the electrical stimulation and combined groups. All groups presented similar improvements in torque, electrical activity and health status.. Electrical stimulation alone or in combination with laser therapy generated positive effects on all evaluated parameters. Laser therapy increased health status and electrical activity, but had no effect on muscle mass.

Topics: Aged; Anthropometry; Combined Modality Therapy; Electric Stimulation Therapy; Electromyography; Female; Health Status; Humans; Isometric Contraction; Knee Joint; Low-Level Light Therapy; Middle Aged; Muscle, Skeletal; Osteoarthritis, Knee; Severity of Illness Index; Single-Blind Method; Torque

Strengthening training (ST) and whole body vibration training (WBV) alone may improve symptoms of osteoarthritis of the knee. In this study, we investigated the effect of adding WBV training to quadriceps and hamstring muscles strengthening training on functional activity, pain, quality of life and muscle strength in patients with knee osteoarthritis. 28 volunteers were randomly allocated to two groups; 1) quadriceps and hamstring muscles strengthening training (ST group, 13 patients) and 2) quadriceps and hamstring muscles strengthening training along with WBV training (ST + WBV group, 15 patients). The treatment protocol for both groups involved 3 sessions per week for 8 weeks. All measurements were performed before and after intervention. The measurements included: pain by means of a visual analogue scale (VAS), quality of life by means of the WOMAC scale, functional activity by the 2 min walking test (2MWT), time up & go test (TUGT) and 50-foot walking test (50FWT) and the muscle peak torque (MPT), total work (TW) and muscle power (MP) as muscle performance of quadriceps and hamstring muscles by an Isokinetic Biodex machine. After intervention, the comparison of mean changes between two groups showed improvement in the WBV + ST group in terms of 2MWT, MPT, TW and MP variables (P < 0.05). However, no significant difference was found between the experimental groups in term of pain, quality of life, TUGT and 50FWT. These results suggest that adding whole body vibration training to strengthening training may provide better treatment effects for patients with knee osteoarthritis.

Topics: Adult; Aged; Exercise Therapy; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Physical Therapy Modalities; Quadriceps Muscle; Quality of Life; Range of Motion, Articular; Torque; Vibration

This study investigated the effect of a 12-week recreational skiing intervention on lower limb muscle strength and cardiorespiratory fitness in participants with unilateral total knee arthroplasty (TKA). Twenty-seven older adults (70 ± 5 years) were assigned to the intervention (n = 13) or control group (n = 14) after surgery (2.5 ± 1 years). Leg muscle strength was measured using an IsoMed 2000 dynamometer and cardiorespiratory fitness was determined by cycle ergometry before and after the intervention as well as after an 8-week retention period. The skiing intervention led to increased muscle strength in the operated leg during unilateral single joint isometric extension (maximal force: 11%; P < 0.05; rate of torque development: 24%; P < 0.05) and during the unilateral multi-joint isokinetic single leg strength test (8%; P < 0.05). This resulted in a decreased asymmetry index in the isokinetic test (13% to 5%; P < 0.05). These adaptations remained unchanged toward the retention test. No effect was observed for cardiorespiratory fitness. The results demonstrate that muscle contraction forces required during recreational skiing in individuals with TKA seem adequate and effective to increase quadriceps and hamstrings muscle strength in the initially weaker operated leg and to reduce an augmented post-operative asymmetry index.

Topics: Aged; Arthroplasty, Replacement, Knee; Exercise Test; Female; Heart Rate; Humans; Knee Joint; Male; Middle Aged; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Oxygen Consumption; Physical Fitness; Quadriceps Muscle; Skiing; Torque

This study investigated the effectiveness of recreational skiing as an intervention to improve quadriceps muscle architecture, strength, and antagonistic co-activation in patients with unilateral total knee arthroplasty (TKA). Hence, patients with TKA were assigned to either an intervention group (IG) or control group (CG). The IG completed a 12-week guided skiing program whereas the CG was instructed not to change their daily routines for the same period and was not allowed to ski. Before, after the intervention/after an 8-week retention period m. rectus femoris (RF) cross-sectional area (CSA), m. vastus lateralis muscle thickness, fascicle length, and pennation angle were measured with ultrasonography, while isometric (90° knee angle) knee extension, flexion torque and m. biceps femoris co-activation were assessed on an isokinetic dynamometer in 26 patients. There were significant and stable increases in RF CSA for the operated (10%; P < 0.05) and non-operated leg (12%; P < 0.01) after the training period in the IG whereas no changes were observed for the CG (all P > 0.05). There were no significant effects for other parameters (all P > 0.05). Overall, the skiing intervention was successful in increasing muscle mass in TKA older patients.

Topics: Adaptation, Physiological; Aged; Arthroplasty, Replacement, Knee; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Organ Size; Osteoarthritis, Knee; Quadriceps Muscle; Skiing; Torque; Ultrasonography

The aim of this study was to evaluate the effect of knee position during wound closure (flexed vs. extended) in total knee arthroplasty on knee strength and function, as determined by knee society scores and isokinetic testing of extensor and flexor muscle groups.. In a prospective, randomized, double-blind trial, 29 patients were divided in two groups: for Group 1 patients, surgical closing was performed with the knee extended, and for Group 2 patients, the knee flexed at 90°. All the patients were treated with the same anaesthesia method, surgical team, surgical technique, prosthesis type, and rehabilitation process. American Knee Society Score values and knee flexion degrees were recorded. Isokinetic muscle strength measurements of both knees in flexion and extension were taken using 60° and 180°/s angular velocity. The peak torque and total work values, isokinetic muscle strength differences, and total work difference values were calculated for surgically repaired and healthy knees.. No significant difference in the mean American Knee Society Score values and knee flexion degrees was observed between the two groups. However, using isokinetic evaluation, a significant difference was found in the isokinetic muscle strength differences and total work difference of the flexor muscle between the two groups when patients were tested at 180°/s. Less loss of strength was detected in the isokinetic muscle strength differences of the flexor muscle in Group 2 (-4.2%) than in Group 1 (-23.1%).. For patients undergoing total knee arthroplasty, post-operative flexor muscle strength is improved if the knee is flexed during wound closure.. II.

Topics: Aged; Arthroplasty, Replacement, Knee; Double-Blind Method; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Posture; Prospective Studies; Range of Motion, Articular; Recovery of Function; Torque

Double blind pre-test post-test control group design.. To compare the isokinetic quadriceps torque, standardized stair-climbing task (SSCT) and pain during SSCT between subjects diagnosed with knee osteoarthritis pre and post kinesio tape (KT) application with and without tension.. Strength of the quadriceps and torque producing capability is frequently found to be compromised in knee osteoarthritis. The efficacy of KT in improving isokinetic quadriceps torque in knee osteoarthritis is unknown, forming the basis for this study.. Forty subjects were randomly allocated to either the experimental (therapeutic KT with tension) or control group (sham KT without tension) with the allocation being concealed. Pre and post test measurements of isokinetic quadriceps torque, SSCT and pain during SSCT were carried out by a blinded assessor.. A large effect size with significant improvements in the peak quadriceps torque (concentric and eccentric at angular velocities of 90° per second and 120° per second), SSCT and pain were obtained in the experimental group when compared to the control group.. Application of therapeutic KT is effective in improving isokinetic quadriceps torque, SSCT and reducing pain in knee osteoarthritis.

Topics: Athletic Tape; Chi-Square Distribution; Confidence Intervals; Double-Blind Method; Exercise Therapy; Female; Humans; Isotonic Contraction; Kinesiology, Applied; Male; Middle Aged; Multivariate Analysis; Muscle Strength; Osteoarthritis, Knee; Pain Measurement; Patient Satisfaction; Quadriceps Muscle; Range of Motion, Articular; Reference Values; Torque; Treatment Outcome

Femorotibial knee osteoarthritis is associated with muscle weakness in the lower limbs, particularly in the quadriceps, which results in disease progression. The interest of having muscular strengthening as part of the therapeutic arsenal for the medical treatment of knee osteoarthritis is now well established.The functional disability induced by knee osteoarthritis manifests itself principally when walking, notably downhill, during which the muscles are called upon to contract eccentrically.We can therefore think that eccentric muscular strengthening could bring a functional benefit that is superior to concentric muscular strengthening.. This is a prospective, randomized, bicenter, parallel-group, international study. Eighty patients aged from 40 to 75 years old, suffering from medical-stage knee osteoarthritis, will undertake 6 weeks of isokinetic muscular strengthening. Randomization determines the mode of muscular strengthening: either exclusively eccentric or exclusively concentric.The principal objective is to demonstrate the superiority of the improvement in the quadriceps isokinetic torque after isokinetic muscular strengthening by the eccentric mode compared to the concentric mode.The following parameters are also evaluated: the variations in the level of pain, the parameters of walking (maximum speed over 10 and 200 meters, analysis on a computerized Gaitrite™ treadmill), static equilibrium (on a FUSYO™ force platform), and the functional status of the patient using the Western Ontario and MacMaster Universities osteoarthritis index (WOMAC) questionnaire after the strengthening period and at 6 months.. A better knowledge of the most effective mode of muscular strengthening is needed to optimize the functional benefits to the patients. In case of superiority in terms of efficacy of the eccentric mode, the latter could be given priority in the rehabilitation treatment of knee osteoarthritis patients.. Clinical trials.gov number: NCT01586130.

Topics: Adult; Aged; Biomechanical Phenomena; Clinical Protocols; Exercise Test; Exercise Therapy; Female; France; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Pain Measurement; Prospective Studies; Quadriceps Muscle; Research Design; Surveys and Questionnaires; Time Factors; Torque; Treatment Outcome

The purposes of this study were to determine 1) whether sex differences in quadriceps torque and isotonic power persist when controlling for muscle volume (i. e., torque/muscle volume and power/muscle volume) in participants with knee osteoarthritis (OA) and 2) the factors responsible for potential sex differences. Isometric torque, isotonic power (the product of torque and velocity, measured at 10, 20, 30, 40 and 50% maximal voluntary contraction; MVC) and maximal unloaded velocity were assessed in men (n=16, mean age=62.1 ± 7.2) and women (n=17, mean age=60.4 ± 4.3) with knee OA. Torque and power were normalized to muscle volume. The interpolated twitch technique was used to measure voluntary activation (VA) and evoked twitch and torque-frequency characteristics were measured to obtain information about muscle fibre distribution. Torque and power at all loads were significantly lower in women (p<0.05). Sex differences in power were reduced by 50% when controlling for muscle volume but were still significant at 10-40% MVC (p<0.05). No differences in VA, torque-frequency properties or time-to-peak tension of the evoked twitch were observed (p>0.05). These results suggest that only minor sex differences in torque and power persist when controlling for muscle volume. As VA and contractile property differences were not observed, other factors seem to be responsible.

Topics: Aged; Female; Humans; Isometric Contraction; Male; Middle Aged; Muscle Fibers, Skeletal; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Sex Factors; Torque

Osteoarthritis is a common musculo-skeletal problem accompanied with muscle weakness. Muscle weakness may be readily improved by resistance training. Greater muscle strength has been associated with a lower knee joint loading rate.. We conducted a single-blind randomized controlled trial of 54 female patients with osteoarthritis in at least one knee, according to the American College of Rheumatology clinical criteria. Patients were randomized into a 6-month high intensity progressive resistance training or a sham-exercise program. The primary outcomes were first peak knee and hip adduction moment measured using three-dimensional gait analysis at self-selected habitual and maximal speeds. Secondary outcomes were sagittal plane knee and hip moments, peak muscle strength, gait speed, and self-reported knee osteoarthritis symptoms measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC).. Six months of high intensity resistance training did not change the first peak knee or hip adduction moment at either habitual or maximum walking speeds (P>0.413) compared to the sham-exercise. However, the second peak hip adduction moment (P=0.025) and WOMAC pain score (P<0.001) were reduced significantly in both groups over time, but there was no group effect. The changes in the second peak hip adduction moment were inversely related to the changes in the WOMAC pain score (r=-0.394, P=0.009).. Muscle strength training in women with osteoarthritis, while effective for reducing osteoarthritis symptoms, appeared to operate through mechanisms other than improved knee or hip joint loading, as paradoxically, improved symptoms were related to decreases of hip adduction moment in late stance.

Topics: Aged; Female; Gait; Gait Disorders, Neurologic; Humans; Leg; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Resistance Training; Torque; Treatment Outcome

Our study was conducted to compare radiographic alignments and functional outcomes with 2 approaches to minimal-incision total knee arthroplasty (TKA): the minimal-incision medial parapatellar (MP) approach and the quadriceps-sparing (QS) approach with side-cutting instruments. Sixty patients (80 knees) with primary osteoarthritis were randomly assigned to receive MP or QS TKA. Postoperative alignment of the femoral component was significantly less valgus, and postoperative alignment of the tibial component was significantly more varus with the QS approach than with the MP approach. One tibial outlier and 3 femoral outliers were observed with QS TKA. The overall postoperative hip-knee-ankle axis was more varus, and surgical time was longer with QS TKA. Short-term isokinetic peak muscle torque, postoperative pain, and functional outcomes did not differ between the approaches.

Topics: Aged; Aged, 80 and over; Arthroplasty, Replacement, Knee; Biomechanical Phenomena; Bone Malalignment; Female; Humans; Knee Joint; Knee Prosthesis; Male; Middle Aged; Minimally Invasive Surgical Procedures; Muscle Strength; Osteoarthritis, Knee; Pain, Postoperative; Prospective Studies; Quadriceps Muscle; Radiography; Single-Blind Method; Torque; Treatment Outcome

The purpose of this study is to present midterm results of NexGen LPS (Zimmer, Warsaw) rotating platform total knee arthroplasty. A prospective consecutive series of 50 primary rotating platform total knee replacements in 43 patients were clinically and radiographically evaluated at a mean follow-up of 46.4 (range 30-78) months. There were 12 men (30%) and 31 women (70%) with an average age of 72.3 years (range 55-85). All implants were cruciate-substituting and cemented. Patients were assessed using the Knee Society Clinical Rating System and the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Pre-operatively, the mean knee score was 50.7 points (SD 15.1) and the mean function score was 40.5 points (SD 22.7). Post-operatively the mean knee score was 91.6 (SD 6.5) and the mean function score was 85.9 (SD 17.4). No sign of component loosening or osteolysis could be identified. The NexGen LPS rotating platform total knee replacement design provided excellent mid-term clinical and radiographical results.

Topics: Aged; Aged, 80 and over; Arthritis, Rheumatoid; Arthroplasty, Replacement, Knee; Equipment Design; Female; Follow-Up Studies; Humans; Male; Middle Aged; Osteoarthritis, Knee; Prospective Studies; Radiography; Recovery of Function; Severity of Illness Index; Shear Strength; Torque; Treatment Outcome

. An abnormally high knee adduction moment increases the medial tibiofemoral compartment load at the knee during gait, and is an important biomechanical marker of joint pathology. This cross-sectional study examines the relationship between the knee adduction moment and knee pain in middle-aged women without radiographic knee osteoarthritis (OA).. Three-dimensional Vicon gait analyses were performed on 20 women who had knee pain but no radiological evidence of joint pathology.. In multivariate analysis, the peak knee adduction moment during the late stance phase of gait was inversely associated with knee pain [beta: -10.1 (95% CI -17.6, -2.7), p = 0.01] after adjustment for body mass index (BMI) and age. This explained that the knee adduction moment during late stance contributed 32% of the variance in knee pain. The peak knee adduction moment during early stance was not significantly associated with knee pain prior to and after adjustment for BMI and age.. There is a significant inverse association between the peak knee adduction moment during late stance and the amount of knee pain experienced by women without radiographic evidence of joint pathology. This may represent a compensatory mechanism to reduce medial tibiofemoral joint load in the setting of knee pain.

Topics: Arthralgia; Female; Humans; Knee Joint; Middle Aged; Muscle Contraction; Muscle, Skeletal; Osteoarthritis, Knee; Radiography; Range of Motion, Articular; Statistics as Topic; Torque

The purposes of this study were to assess a) the effectiveness of Masai Barefoot Technology (MBT) shoe in reducing knee pain in persons with knee osteoarthritis (OA) and (b) changes in balance, ankle and knee ROM, and ankle strength compared with a high-end walking shoe for 12 wk.. The research design was a randomized controlled trial (123 subjects, knee OA). Subjects were randomized to a MBT (N = 57) or a control shoe (N = 66). A Western Ontario and McMaster Universities (WOMAC) OA index, BMI, balance, active ROM, and ankle torque were quantified at week 0, 3, 6, 9, and 12. Two-sample t-tests were done for between-group comparisons.. There was no significant difference between groups in total pain score. A significant reduction over the 12-wk period was found for both shoe conditions (-42/500 or 25.6% MBT, -46.2 or 27.1% control). There was no significant group difference in pain during walking (t = -1.09, P = 0.28). Pain during walking was significantly reduced by 5.2/100 mm in the MBT and 9.7/100 mm in the control group. Total pain showed a significant reduction for the MBT -27.4/500 (-16.6%) and the control group -28.9/500 (-17.0%) between baseline and week 3. Between week 3 and 6, there was a significant reduction for the MBT group only (-27.2/500 or -20.0%). There was a significant increase in the static balance between baseline and 12 wk in the MBT group only, although the difference between groups was not significant.. The results indicate that special shoe interventions can reduce pain in subjects with moderate knee OA.

Topics: Adult; Arthralgia; Equipment Design; Female; Humans; Male; Middle Aged; Osteoarthritis, Knee; Postural Balance; Posture; Shoes; Surveys and Questionnaires; Torque; Walking

Conservative treatment for osteoarthritis often involves educating the patient in methods of decreasing the load transmitted through the diseased joint. The use of a cane is one such method and the correct placement of the cane with respect to an abnormal knee joint is crucial. The purpose of this study was to compare effects on knee moments of force of contralateral versus ipsilateral cane usage in female subjects with osteoarthritic knees.. A convenience sample of 14 subjects volunteered for this study. Subjects walked over force platforms while ground reaction force and three-dimensional kinematic data were captured using a Vicon 370 System. The subjects were tested walking: (a) unaided, (b) with ipsilateral cane, and (c) with contralateral cane. Inverse dynamics were employed to calculate temporal-spatial, kinematic and kinetic variables. Dependent variables included hip and knee frontal plane and sagittal plane moments of force, walking speed, cadence and stride length. Repeated measures ANOVA assessed differences among walking conditions.. Subjects walked significantly faster in the unaided gait condition owing to a higher cadence. Ipsilateral cane use resulted in significantly larger hip (versus contralateral P=0.018; versus unaided P=0.036) and knee (versus contralateral P=0.043; versus unaided P=0.030) frontal plane peak moments during gait. Contralateral cane placement was associated with the smallest peak knee abductor (P=<0.001) and flexor (P=<0.001) moments. Knee deformity (varus or valgus) did not have any significant effect on any variable possibly due to small sample size.. The results suggest that as is the case for the hip contralateral cane placement is the most efficacious for persons with knee osteoarthritis. In fact, no cane use may be preferable to ipsilateral cane usage as the latter resulted in the highest knee moments of force, a situation which may exacerbate pain and deformity.

Topics: Adaptation, Physiological; Canes; Computer Simulation; Diagnosis, Computer-Assisted; Female; Gait; Humans; Knee Joint; Middle Aged; Models, Biological; Osteoarthritis, Knee; Stress, Mechanical; Torque

To determine if women's dress shoes with heels of just 1.5 in (3.8 cm) in height increases knee joint torques, which are thought to be relevant to the development and/or progression of knee osteoarthritis (OA) in both the medial and patellofemoral compartments.. Randomized controlled trial.. A 3-dimensional motion analysis gait laboratory.. Twenty-nine healthy young women (age, 26.7+/-5.0 y) and 20 healthy elderly adult women (age, 75.3+/-6.5 y).. Not applicable.. Peak external varus knee torque in early and late stance and prolongation of flexor knee torque in early stance. Three-dimensional data on lower-extremity torques and motion were collected during walking while (1) wearing shoes with 1.5-in high heels and (2) wearing control shoes without any additional heel. Data were plotted and qualitatively compared; major peak values and timing were statistically compared between the 2 conditions using paired t tests.. Peak knee varus torque during late stance was statistically significantly greater with the heeled shoes than with the controls, with increases of 14% in the young women and 9% in the elderly women. With the heeled shoes, the early stance phase knee flexor torque was significantly prolonged, by 19% in the young women and by 14% in elderly women. Also, the peak flexor torque was 7% higher with the heeled shoe in the elderly women.. Even shoes with moderately high heels (1.5 in) significantly increase knee torques thought to be relevant in the development and/or progression of knee OA. Women, particularly those who already have knee OA, should be advised against wearing these types of shoes.

Topics: Adult; Aged; Biomechanical Phenomena; Disease Progression; Female; Gait; Heel; Humans; Knee Joint; Osteoarthritis, Knee; Risk Reduction Behavior; Shoes; Torque

To investigate the effects of ultrasound (US) in isokinetic muscle strengthening exercises on functional status of patients with knee osteoarthritis (OA).. Effectiveness of isokinetic muscle strengthening exercises for treatment of periarticular soft tissue disorders was compared with and without pulsed and continuous US.. Outpatient exercise program in a Taiwan medical university hospital.. One hundred twenty subjects with bilateral knee OA (Altman grade II).. Subjects were randomized sequentially into 1 of 4 groups. Group I received isokinetic muscular strengthening exercises, group II received isokinetic exercise and continuous US, group III received isokinetic exercise and pulsed US treatment, and group IV was the control group.. Therapeutic effects of isokinetic exercise were evaluated by changes in ambulation speed and the Lequesne index. In addition, changes in knee range of motion (ROM), visual analog scale for pain, and muscle peak torques during knee flexion and extension were compared. Compliance in each group was recorded.. Each treated group had increased muscle peak torques and significantly reduced pain and disability after treatment and at follow-up. However, only patients in groups II and III had significant improvement in ROM and ambulation speed after treatment. Fewer participants in group III discontinued treatment due to knee pain during exercise. Patients in group III also showed the greatest increase in walking speed and decrease in disability after treatment and at follow-up. Gains in muscular strength in 60 degrees /s angular velocity peak torques were also noted in groups II and III. However, group III showed the greatest muscular strength gains with 180 degrees /s angular velocity peak torques after treatment and follow-up.. US treatment could increase the effectiveness of isokinetic exercise for functional improvement of knee OA, and pulsed ultrasound has a greater effect than continuous US.

Topics: Adult; Aged; Analysis of Variance; Disability Evaluation; Exercise Therapy; Female; Humans; Male; Middle Aged; Osteoarthritis, Knee; Pain Measurement; Patient Compliance; Range of Motion, Articular; Torque; Treatment Outcome; Ultrasonic Therapy; Walking

To examine if the addition of transcutaneous electrical nerve stimulation (TENS) to exercise training would produce better physical outcomes than TENS or exercise alone in people with knee osteoarthritis.. Sixty-two subjects were randomly allocated to four groups.. Patients received either (1) TENS, (2) placebo stimulation, (3) exercise training, or (4) TENS and exercise training five days a week for four weeks.. The isometric peak torque, spatiotemporal gait parameters and range of knee movement were assessed in treatment session1, session10 and session20 and the four-week follow-up.. By session20, the TENS and exercise group demonstrated an average of 26.6% cumulative gain in the knee extensor peak torque for the different knee positions (all p < 0.05). Although the between-group difference was short of being statistically significant, the gain found in the TENS and exercise group was greater than that found in the other three groups. The TENS and exercise group also tended to show greater cumulative increase in stride length (12.6%, p = 0.006), walking cadence (9.3%, p = 0.098) and gait velocity (22.4%, p = 0.034) than the other groups. By session20, it was the only group that produced a significant increase in the range of knee motion during walking (12.0%, p = 0.000). The TENS group and the exercise group both demonstrated some improvements in the above physical outcomes, but negligible change was found in the group receiving placebo stimulation (all p > 0.05).. No significant difference was found among the four treatment protocols, but the addition of TENS to exercise training tended to produce the best overall improvement in physical outcomes in people with knee osteoarthritis.

Topics: Aged; Combined Modality Therapy; Exercise Therapy; Female; Gait; Humans; Male; Middle Aged; Osteoarthritis, Knee; Outcome Assessment, Health Care; Range of Motion, Articular; Torque; Transcutaneous Electric Nerve Stimulation; Walking

The goals of the study were to measure the force applied to the lateral side of the knee by a valgus loading brace designed for patients with medial compartment osteoarthritis (OA) and to compare the varus moment at the knee during level gait with and without the brace.. Five subjects diagnosed with medial compartment OA were fitted with a custom Monarch valgus loading knee brace. A 3-dimensional videobased motion analysis system and force plate information were used to calculate forces and moments at the knee. An instrumented condylar bladder was used to determine the force applied to the knee by the brace. The varus moments for the braced and unbraced trials were compared during gait at 15%, 20%, 25%, and 30% of stance.. The Monarch brace significantly reduced the varus moment at 20% and 25% of stance. The valgus force measured with the custom condylar bladder remained fairly constant throughout the first 80% of the stance phase.. The reduced various moment observed for the braced condition demonstrates the biomechanical function of the brace in 5 subjects and may contribute to a reduction of pain for patients with medial compartment OA.

Topics: Activities of Daily Living; Adult; Analysis of Variance; Biomechanical Phenomena; Braces; Equipment Design; Female; Gait; Humans; Male; Middle Aged; Osteoarthritis, Knee; Pain; Range of Motion, Articular; Torque; Treatment Outcome; Videotape Recording; Weight-Bearing

The study investigated the effects of periarticular knee pressure stimuli on quadriceps strength and neuromuscular activity in subjects with knee osteoarthritis. Twenty-five subjects with knee osteoarthritis and 25 age-matched healthy controls performed maximal voluntary knee extension tasks on an isometric dynamometer. Three different pressure stimuli (no-pressure, 60-mmHg, 120-mmHg) were applied using a sphygmomanometer via the cuff covering the knee joint. Peak torque and root-mean-square peak of rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) were collected and normalized for the no-pressure condition (nTorque-peak and nRMS-peak). Normalized Torque-peak increased from no-pressure to 60-mmHg and 120-mmHg in patients, which revealed higher nTorque-peak during 60-mmHg (MD: 10.9%, IC

Topics: Electromyography; Humans; Isometric Contraction; Knee Joint; Muscle, Skeletal; Osteoarthritis, Knee; Quadriceps Muscle; Torque

A novel virtual game system Knee Biofeedback Rehabilitation Interface for game-based home therapy (KneeBright) was developed for strength training using integrated electromyography biofeedback of the quadriceps muscle to control the game. The study aimed to compare the KneeBright and electromyography biofeedback interface among patients with knee osteoarthritis.. Controlled before and after design.. Nineteen patients with knee osteoarthritis took part in this laboratory-based study. Exercise sessions took place on 2 separate days. During session 1, participants used a conventional electromyography biofeedback system while performing 3 sets of lower body exercises with emphasis on maximal muscle activation, endurance, and precision. During session 2, participants used the KneeBright game to match the exercise sets in the first session. For both sessions, knee extension torque during the isometric muscle activation exercises and time to voluntary additional exercise were recorded. Patient engagement was assessed using the technology acceptance model and System Usability Score questionnaires.. The peak knee extension torque produced during the control exercise session and the KneeBright exercise session were positively correlated. Knee extension torque generated during KneeBright game exercise sessions was increased by an average of 25% compared to the control sessions (2.14 vs 1.77 N·m/kg, P = .02). The mean technology acceptance model score for the KneeBright system was 3.4/5 and the mean System Usability Score was 79, both indicating positive patient engagement.. Patients using the KneeBright game produced greater knee torque than patients using the conventional system, had positive levels of engagement, and exercised longer with the KneeBright game.

Topics: Biofeedback, Psychology; Electromyography; Feasibility Studies; Humans; Isometric Contraction; Osteoarthritis, Knee; Quadriceps Muscle; Torque; Video Games

Knee osteoarthritis (OA) is a prevalent disabling disease among women and quadriceps weakness is attributed to one of the causes of knee pain (KP) and disability. The study aimed to test the correlation of eccentric quadriceps torque (EQT) with 2 subscales of the reduced WOMAC questionnaire (KP and physical function) and extension lag range of motion (ROM) at the knee joint in osteoarthritic women. A cross-sectional design was used. A total of 70 patients (mean age 41.1 years) who had grade I or II knee OA participated in the study. The pearson correlation coefficient was used to test the correlation between the EQT and 2 subscales of the reduced WOMAC questionnaire and extension lag ROM. EQT presented a significant moderate negative correlation with pain (r = -0.489, P < .001) and physical function (r = -0.425, P < .001), and low positive correlation with available ROM (R = 0.349, P < .001). KP, physical function, and extension lag in the early stages of knee OA in women are associated with EQT. Therefore, designing a rehabilitation program that has eccentric quadriceps strengthening exercises may improve KP and physical activities, but more randomized controlled trials are needed to verify this.

Topics: Adult; Cross-Sectional Studies; Female; Humans; Knee Joint; Muscle Strength; Osteoarthritis, Knee; Pain; Quadriceps Muscle; Range of Motion, Articular; Torque

In medial knee osteoarthritis (knee OA), compensatory overstrain of the rectus femoris (RF) muscle leads to its hypertrophy. We hypothesize that besides hypertrophy of the RF, a prominent flattening of the central aponeurosis (CA) curvature is also indicative of RF. This study aims to evaluate the structural changes in the CA and clarify the conditions associated with RF overstrain in knee OA.. Twenty-three legs of 20 elderly without knee OA (elderly group) and 26 legs of 20 individuals with K-L grade II knee OA (knee OA group) with typical "comma"-shaped CA participated in this study.. The knee extension torque (Nm/kg) in the sitting position, the thickness of the RF and vastus intermedius (VI) muscles (VI), and change in CA curvature (%Curvature) were measured at the mid-thigh by ultrasonography.. The knee extension torque was not significantly different between the two groups. Compared to the elderly group, the knee OA group had significantly thicker RF at rest, while the VI thickness during contraction was significantly smaller. The %Curvature was significantly higher in the knee OA group than in the elderly group.. In the knee OA group, the RF was hypertrophic with a more pronounced CA flattening during muscle contraction, although the other quadriceps muscles were atrophic, suggesting an overstrained RF. Assessing thickness and CA curvature of the RF is, therefore, useful and simple for evaluating overstrain caused by RF compensation.

Topics: Aged; Aponeurosis; Humans; Osteoarthritis, Knee; Quadriceps Muscle; Torque; Ultrasonography

As the population ages, there is a growing burden owing to musculoskeletal diseases, such as knee osteoarthritis, and subsequent functional decline. In the absence of a cure, there is a need to identify factors amenable to intervention to prevent or slow this process. The Multicenter Osteoarthritis Study cohort was developed for this purpose. In this study, associations between variability in peak knee flexor and extensor torque at baseline and worsening of pain and physical function over the subsequent 60 mos were assessed in a cohort of 2680 participants. The highest quartile of baseline knee flexor torque variability was found to be associated longitudinally with worsening pain (fourth quartile ß estimate, mean ± SE, 0.49 ± 0.19; P = 0.0115; with R2 = 0.28 and P for trend across quartiles = 0.0370) and physical function scores (fourth quartile ß estimate, mean ± SE, 1.39 ± 0.64; P = 0.0296; with R2 = 0.25 and P for trend across quartiles = 0.0371), after adjusting for baseline knee osteoarthritis and maximum knee flexor torque. There were no associations between baseline knee extensor torque and worsening pain or physical function by 60 mos. The presence of greater variability in maximum knee flexor strength may identify patients who may benefit from therapies aimed at preventing worsening knee pain and physical function.

Topics: Aged; Female; Follow-Up Studies; Humans; Knee Joint; Longitudinal Studies; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Pain Measurement; Risk Factors; Torque; United States

The aim of the study was to determine the effect of comorbidities on physical function and quality of life of patients at 3 mos after total knee arthroplasty.. Data from 140 patients who underwent a primary unilateral total knee arthroplasty were examined retrospectively. Comorbidities were osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following: range of motion, stair climbing test, 6-min walk test, Timed Up and Go Test, peak torque of the knee extensor and flexor, instrumental gait analysis, Western Ontario McMaster Universities Osteoarthritis Index, and EuroQoL five-dimension questionnaire.. Univariate analyses revealed that osteoporosis led to a significantly longer time to complete the stair climbing test-ascent, stair climbing test-descent, and Timed Up and Go Test and to lower scores for the 6-min walk test and peak torque of the knee extensor. Patients with degenerative spine disease showed significant negative scores for knee extension range of motion. Diabetes showed a negative correlation with peak torque of the knee extensor and knee flexion range of motion, as well as a higher Western Ontario McMaster Universities Osteoarthritis Index-stiffness score. Multivariable linear regression analysis showed that Western Ontario McMaster Universities Osteoarthritis Index-stiffness remained independently associated with diabetes. Six-minute walk test, Timed Up and Go Test, stair climbing test-ascent, and peak torque of the knee extensors showed a significant association with osteoporosis.. Comorbidities, particularly osteoporosis and diabetes, affect short-term functional outcomes 3 mos after total knee arthroplasty.

Topics: Aged; Arthroplasty, Replacement, Knee; Comorbidity; Diabetes Mellitus; Disability Evaluation; Female; Gait Analysis; Humans; Hypertension; Knee Joint; Linear Models; Male; Osteoarthritis, Knee; Osteoporosis; Postoperative Period; Quality of Life; Range of Motion, Articular; Recovery of Function; Retrospective Studies; Sarcopenia; Spinal Diseases; Stair Climbing; Time and Motion Studies; Torque; Treatment Outcome; Walk Test

This study aimed to determine deficits in knee extensor muscle function through the torque-time and torque-velocity relationships and whether these deficits are associated with reduced functional performance in postmenopausal women with knee osteoarthritis (KOA). A clinical sample of postmenopausal women with established KOA (n = 18, ≥55 years) was compared to an age-matched healthy control sample (CON) (n = 26). The deficits in different parameters of the knee extensor torque-time (maximal isometric torque and rate of torque development) and torque-velocity relationship (maximum muscle power, maximal velocity and torque at 0-500°·s

Topics: Aged; Cross-Sectional Studies; Exercise Test; Female; Humans; Middle Aged; Muscle Weakness; Osteoarthritis, Knee; Postmenopause; Torque

Osteoarthritis (OA) is the most common chronic joint condition. Muscle dysfunction plays a critical role in the pathogenesis of knee OA.. It has been suggested that the agonist-antagonist strength relationship for the knee may be better described by a functional hamstring/quadriceps (H/Q) ratio (Hconcentric/Qeccentric: the representative of knee flexion and Qeccentric/Hconcentric: the representative of knee extension). Therefore, in this study, the authors aimed to investigate this ratio and its importance for knee OA.. Cross-sectional study.. Research clinic. Patients or Other Participant(s): Twenty healthy women and 20 women with grade 2 or grade 3 primer knee OA between the age of 50 and 80 years were included in this study.. Concentric and eccentric peak torque of quadriceps and hamstring muscles were evaluated for all individuals in patient and control groups with a Cybex isokinetic device. Functional H/Q ratio is calculated manually.. Functional H/Q torque ratios were analyzed between the patients with OA and healthy individuals by using the isokinetic system.. The values of peak torque of hamstring concentric and eccentric and quadriceps concentric for the patient group were significantly lower than the control group (P < .05). No statistically important difference was found for quadriceps eccentric peak torque between 2 groups (P > .05). H/Q ratio for extension in the patient group was significantly higher than the control group (P < .05), whereas the H/Q ratio for flexion in the patient group was significantly lower than the control group (P < .05).. This study showed the weakness of both quadriceps and hamstring muscles in patients with knee OA. The combination of functional H/Q ratio with hamstring and quadriceps muscles concentric and eccentric strength values can help to analyze the knee functions and develop preventive-therapeutic approaches for knee OA.

Topics: Aged; Aged, 80 and over; Case-Control Studies; Female; Hamstring Muscles; Humans; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Torque

Patellofemoral joint (PFJ) osteoarthritis may occur after anterior cruciate ligament reconstruction (ACLR). The mechanisms underpinning the development of PFJ osteoarthritis are not known but may relate to altered PFJ loading. Few studies have assessed PFJ loads during high-impact tasks, such as running, beyond the acute rehabilitation phase (ie, >12 months) after ACLR.. The purpose was to compare between-limb joint angles, joint moments, and PFJ contact force during running in individuals at 12 to 24 months after unilateral ACLR. We hypothesized that peak knee flexion angle, knee extension moment, and PFJ contact force during stance would be lower in the ACLR limb compared with the uninjured limb.. Controlled laboratory study.. A total of 55 participants (mean ± SD age, 28 ± 7 years), 12 to 24 months after ACLR, ran at a self-selected speed (2.9 ± 0.3 m/s). Measured kinematics and ground-reaction forces were input into musculoskeletal models to calculate joint moments and muscle forces. These values were subsequently input into a PFJ model to calculate contact force peak and impulse. Outcome measures were compared between the ACLR and uninjured limbs.. In the ACLR limb, compared with the uninjured limb, the PFJ contact force displayed a lower peak (ACLR, 6.1 ± 1.3 body weight [BW]; uninjured, 6.7 ± 1.4 BW;. The ACLR limb experienced lower peak PFJ loads during running, explained by a small anterior shift in the foot-ground center of pressure during stance that offloaded the torque demand away from the ACLR knee.. Lower net PFJ loading during running in the ACLR limb more than 12 months after ACLR suggests that underloading might play a role in the onset of PFJ osteoarthritis after ACLR.

Topics: Adolescent; Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Biomechanical Phenomena; Female; Follow-Up Studies; Humans; Male; Middle Aged; Osteoarthritis, Knee; Patellofemoral Joint; Running; Torque; Weight-Bearing; Young Adult

The linear relationship between muscle torque and rate of torque rise/relaxation during rapid muscle contractions has been recently introduced as a novel measure of muscle quickness, termed rate of torque development/relaxation scaling factor (RTD-SF/RTR-SF). Because the standard assessment protocol includes potentially painful muscle contractions, the first purpose of this study was to validate an adapted RTD-SF/RTR-SF protocol for knee extensor muscles that utilizes lower submaximal intensities and can be used in knee osteoarthritis patients.. A cross-sectional study was performed on a group of healthy controls (n = 24) who underwent the standard RTD-SF/RTR-SF protocol (20-80% of maximum) and the knee osteoarthritis group (n = 24) who underwent the adapted protocol (20-60% of maximum). We calculated the RTD-SF, RTR-SF and the linearity (r. The validity of the adapted protocol was acceptable (intraclass correlation coefficient = 0.77-0.93), with low within-participant variation (coefficient of variability <10%) for both outcome measures. Compared with the control group, the knee osteoarthritis group had similar RTD-SF, but lower linearity of RTD-SF (0.90 vs. 0.82). The RTR-SF (8.0/s vs. 6.7/s) and its linearity (0.87 vs. 0.73) were significantly reduced. Comparing the affected and the unaffected leg in the knee osteoarthritis group, the unaffected leg had greater maximal torque (96.2 vs. 84.1 Nm) and higher linearity for RTD-SF (0.86 vs. 0.80) and RTR-SF (0.82 vs. 0.73).. We confirmed the validity of the adapted RTD/RTR-SF protocol and its sensitivity to impairments associated with knee osteoarthritis.

Topics: Aged; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Male; Muscle Contraction; Osteoarthritis, Knee; Torque

Aim of this study was to investigate if knee extensor maximal voluntary contraction (MVC) torque and rate of torque development (RTD) deficits are accompanied by neuromuscular activation failure in patients with knee osteoarthritis (KOA). Nineteen patients with unilateral KOA completed gradual MVCs, from which MVC torque, voluntary activation and maximal EMG activity were recorded, and explosive MVCs, from which RTD and rate of EMG rise were recorded. For gradual MVCs, MVC torque (-28%), voluntary activation (-6%) and maximal EMG activity (-30%) were lower on the involved than on the uninvolved side (p < 0.001). Asymmetries in MVC torque and maximal EMG activity were positively correlated (r = 0.70; p < 0.001). For explosive MVCs, involved-side RTD (-19%) and rate of EMG rise (-20%) were lower compared to the uninvolved side (p < 0.05-0.001). Asymmetries in RTD and rate of EMG rise were positively correlated (r = 0.61-0.80; p < 0.01). Deficits in isometric knee extensor strength were accompanied by neuromuscular activation failure during gradual MVCs and, more importantly, during the early phase of explosive MVCs. Such inability to rapidly activate the quadriceps may have functional consequences and warrants greater attention in the evaluation and rehabilitation of patients with KOA.

Topics: Aged; Female; Humans; Isometric Contraction; Male; Middle Aged; Muscle, Skeletal; Osteoarthritis, Knee; Torque

Following rehabilitation for total knee arthroplasty, "quadriceps avoidance gait", defined by limited knee flexion angle excursion during walking, persists and contributes to poor long-term outcomes. Given the presence of several post-surgical impairments, identifying the contribution of multiple factors to knee flexion angle excursion is important to developing targeted interventions to improve recovery after total knee arthroplasty.. Which outcomes continue to improve following rehabilitation for total knee arthroplasty? What are the primary contributors to impaired knee flexion angle excursion during walking following total knee arthroplasty?. Peak muscle strength and rate of torque development of the quadriceps, hip abductors, and hip external rotators, five-time sit-to-stand test, Knee Injury & Osteoarthritis Outcome Score, and gait mechanics were assessed in 24 participants at three and six months post-surgery. Paired sample t-tests or Wilcoxon Signed-Rank tests were used to compare outcomes between assessments. Stepwise multiple linear regression were used to assess the contribution of each measure to knee flexion angle excursion.. While higher pain levels at three months and greater peak hip external rotation muscle strength at six months contribute to impaired knee flexion angle excursion, quadriceps rate of torque development was the primary contributor to knee flexion angle excursion at both three and six months after surgery. Implementing strategies to maximize quadriceps rate of torque development during rehabilitation may help to reduce quadriceps avoidance gait after total knee arthroplasty.

Topics: Aged; Arthroplasty, Replacement, Knee; Female; Gait; Gait Analysis; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Range of Motion, Articular; Risk Factors; Torque

Muscular (i.e., quadriceps) weakness contributes to disease progression and precedes the appearance of patient-reported symptoms, such as pain and perceived physical dysfunction, in knee osteoarthritis (OA). It is unknown, however, if muscular-based and patient-reported outcomes differentially associate with systemic biomarkers reflective of the local mediators in knee OA. The purpose of this study was to identify if muscular-based and patient-reported outcomes differentially associate with circulating superoxide dismutase (SOD) and cytokines in knee OA. Subjects (n = 29) with pain, muscular weakness, and radiographic evidence (Kellgren-Lawrence grade ≥2) of knee OA in the involved (INV) leg were included in this study. Serum Cu/Zn and Mn SOD and cytokine concentrations were measured in fasting blood samples. Pain and physical dysfunction were subjectively assessed and muscle strength (i.e., peak isometric force and torque, and peak isokinetic-concentric knee-extension and -flexion torques) was determined unilaterally in the INV and non-involved (NI) legs. Peak isometric and peak isokinetic-concentric knee-flexion torques in the INV leg correlated with serum Cu/Zn SOD (both p < 0.05). Peak isometric force and torque and peak isokinetic-concentric knee-extension and -flexion torques in the INV leg correlated with serum Mn SOD (all p < 0.05). Pain and dysfunction inversely associated with serum IL-1β, IL-4, IL-5, IL-12, IL-13, and/or IFN-γ (p < 0.05). Neither SOD associated with pain or dysfunction, and none of the cytokines associated with muscular-based outcomes. We conclude that common outcome measures used in the clinical evaluation of OA differentially associate with circulating SOD and cytokines.

Topics: Biomarkers; Cytokines; Female; Humans; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Pain; Patient Reported Outcome Measures; Quadriceps Muscle; Superoxide Dismutase; Torque

Knee osteoarthritis (OA) is a highly prevalent disease leading to mobility disability in the aged that could, in part, be initiated by age-related alterations in knee mechanics. However, if and how knee mechanics change with age remains unclear.. What are the impacts of age and physical activity (PA) on biomechanical characteristics that can affect the loading environment in the knee during gait?. Three groups (n = 20 each, 10 male and 10 female) of healthy adults were recruited: young (Y, 21-35 years), mid-life highly active (MHi, 55-70 years, runners), and mid-life less active (MLo, 55-70 years, low PA). Outcome measures included knee kinematics and kinetics and co-activation during gait, and knee extensor muscle torque and power collected at baseline and after a 30-minute treadmill trial to determine the impact of prolonged walking on knee function.. At baseline, high-velocity concentric knee extensor power was lower for MLo and MHi compared with Y, and MLo displayed greater early (6.0 ± 5.8 mm) and peak during stance (11.3 ± 7.8 mm) femoral anterior displacement relative to the tibia compared with Y (0.2 ± 5.6 and 4.4 ± 6.8 mm). Also at baseline, MLo showed equal quadriceps:hamstrings activation, while Y showed greater relative hamstrings activation during midstance. The walking bout induced substantial knee extensor fatigue (decrease in maximal torque and power) in Y and MLo, while MHi were fatigue-resistant.. These results indicate that maintenance of PA in mid-life may impart small but measurable effects on knee function and biomechanics that may translate to a more stable loading environment in the knee through mid-life and thus could reduce knee OA risk long-term.

Topics: Adult; Age Factors; Aged; Biomechanical Phenomena; Exercise; Exercise Test; Female; Gait; Hamstring Muscles; Humans; Kinetics; Knee; Knee Joint; Male; Middle Aged; Osteoarthritis, Knee; Quadriceps Muscle; Range of Motion, Articular; Risk Factors; Torque; Young Adult

Topics: Adult; Aged; Cross-Sectional Studies; Disability Evaluation; Exercise Test; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle Strength Dynamometer; Osteoarthritis, Knee; Quadriceps Muscle; Torque

It is believed that Quadriceps strength training may reduce pain and improve functional activity in patients with knee osteoarthritis (OA). This improvement is generally attributed to an increase in quadriceps strength. This study investigated whether quadriceps muscle strength increases with decreasing pain, improving functional activity in knee OA. Twenty-four patients with knee OA participated in an 8-week treatment protocol including traditional physical therapy and strength training 3 sessions per week. Measurements were conducted before and after the intervention and included the peak torque of quadriceps muscle, pain by visual analogue scale (VAS), short Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and functional activity by the 2 minute walking test (2MWT) and time up & go test (TUGT). After the intervention, analysis of data illustrated that changes in quadriceps muscle strength correlated with changes in VAS (r

Topics: Adult; Aged; Arthralgia; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Pain Measurement; Physical Therapy Modalities; Quadriceps Muscle; Quality of Life; Range of Motion, Articular; Resistance Training; Torque; Walk Test

  Central and peripheral neural adaptations have been identified after anterior cruciate ligament (ACL) injury and reconstruction (ACLR) and are hypothesized to contribute to posttraumatic muscle dysfunction. Limited evidence exists about the temporal nature of neuromuscular adaptations during early and late-term phases of recovery after ACLR, and no researchers have studied patients with posttraumatic osteoarthritis..   To compare quadriceps neuromuscular function less than 2 years ( early) and more than 2 years ( late) after ACLR, including in patients who experienced posttraumatic knee osteoarthritis..   Cross-sectional study..   Laboratory..   A total of 72 patients after ACLR, consisting of 34 early (9.0 ± 4.3 months postsurgery), 30 late (70.5 ± 41.6 months postsurgery), and 8 with osteoarthritis (115.9 ± 110.0 months postsurgery), and 30 healthy control volunteers..   Quadriceps function was measured bilaterally during a single visit to determine normalized Hoffmann reflex (H : M ratio), knee-extension maximal voluntary isometric contraction torque (Nm/kg), central activation ratio (%), fatigue index (% decline), and active motor threshold (%). Comparisons were made using 2-way analyses of variance to identify the effect of limb and group on each outcome measure. We calculated Cohen d effect sizes to assess the magnitude of difference between ACLR and matched control limbs for each group..   Compared with healthy control limbs, involved-limb maximal voluntary isometric contraction was lower among all patients after ACLR ( P < .001, Cohen d values = -1.00 to -1.75). The central activation ratio ( P < .001, Cohen d = -1.74) and fatigue index ( P = .003, Cohen d = -0.95) were lower among patients only early after ACLR. The active motor threshold was higher among all patients after ACLR ( P < .001, Cohen d values = -0.42 to -1.56)..   Neuromuscular impairments were present in patients early and late after ACLR, regardless of osteoarthritis status. Quadriceps strength and corticospinal excitability were impaired at each time point compared with values in healthy control individuals, suggesting the need to address cortical function early after ACLR.

Topics: Adaptation, Physiological; Adolescent; Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Cross-Sectional Studies; Female; Humans; Isometric Contraction; Knee Joint; Male; Middle Aged; Neuromuscular Junction; Osteoarthritis, Knee; Quadriceps Muscle; Reflex; Time Factors; Torque; Young Adult

Relationships between quadriceps function and patient-reported outcomes after anterior cruciate ligament reconstruction (ACLR) are variable and may be confounded by including patients at widely different time points after surgery. Understanding these relationships during the clinically relevant phases of recovery may improve our knowledge of specific factors that influence clinical outcomes.. To identify the relationships between quadriceps function and patient-reported outcomes in patients <2 years (early) and >2 years (late) after ACLR, including those with posttraumatic knee osteoarthritis.. Cross-sectional study.. Laboratory.. A total of 72 patients after ACLR: early (n = 34, time from surgery = 9.0 ± 4.3 months), late (n = 30, time from surgery = 70.5 ± 41.6 months), or osteoarthritis (n = 8, time from surgery = 115.9 ± 110.0 months).. The total Knee Injury and Osteoarthritis Outcome Score (KOOS) and Veterans RAND 12-Item Health Survey (VR-12) were used to quantify knee function and global health. Predictors of patient-reported outcomes were involved-limb and symmetry indices of quadriceps function (isokinetic strength [peak torque, total work, average power], maximum voluntary isometric contraction torque, fatigue index, central activation ratio, Hoffmann reflex, active motor threshold) and demographics (age, activity level, pain, kinesiophobia, time since surgery). Multiple linear regression analyses were used to predict KOOS and VR-12 scores in each group.. In the early patients, knee-extensor work, active motor threshold symmetry, pain, and activity level explained 67.8% of the variance in the KOOS score ( P < .001); knee-extensor work, activity level, and pain explained 53.0% of the variance in the VR-12 score ( P < .001). In the late patients, age and isokinetic torque symmetry explained 28.9% of the variance in the KOOS score ( P = .004). In the osteoarthritis patients, kinesiophobia and isokinetic torque explained 77.8% of the variance in the KOOS score ( P = .010); activity level explained 86.4% of the variance in the VR-12 score ( P = .001).. Factors of muscle function and demographics that explain patient-reported outcomes were different in patients early and late after ACLR and in those with knee osteoarthritis.

Topics: Adolescent; Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Cross-Sectional Studies; Female; Humans; Isometric Contraction; Knee Joint; Male; Middle Aged; Osteoarthritis, Knee; Patient Reported Outcome Measures; Quadriceps Muscle; Reflex; Torque; Young Adult

Osteoarthritis is the most prevalent rheumatic disease in the population and is characterized by limitation of main functional activities of daily living, as the gait. Muscle strength is a variable that may be related to performance in daily tasks.Therefore, we to analyze the gait pattern in individuals with knee osteoarthritis (KOA) and to determine associations of gait variables with the level of muscle strength of knee extensors.. Sixty-seven female volunteers divided into 2 groups, a KOA group (KOAG, n = 36, 66.69 ± 7.69 years) and control (n = 31, 63.68 ± 6.97 years), participated in the study. The volunteers walked on a 10-m platform at their usual gait speed, using 2 pressure sensors positioned at the base of the hallux and calcaneus. The mean step time, support and double support times, swing time and gait speed were calculated. The evaluation of the quadriceps isometric torque was performed in an extensor chair, with hip and knee flexion at 90°. The procedure consisted of three maximal contractions of knee extension. Peak torque was determined by the highest torque value obtained after the onset of muscle contraction. For statistical analysis, one-way ANOVA and Pearson's correlation were used, with p <  0.05.. The KOAG had a 54.76% longer support time, a 13% longer step time (p <  0.001), a 30% decrease in swing time (p <  0.001) and a 10.7% decrease in gait speed (p = 0.001) compared with controls. The quadriceps isometric torque was 34% (p = 0.001) lower in the KOAG. There was a correlation between kinematic variables and quadriceps torque.. Weakness of the quadriceps muscle in women with KOA influences gait pattern, resulting in reduced speed associated with a shorter swing time and longer support time.

Topics: Aged; Analysis of Variance; Case-Control Studies; Female; Gait; Gait Analysis; Humans; Isometric Contraction; Middle Aged; Muscle Contraction; Muscle Weakness; Osteoarthritis, Knee; Quadriceps Muscle; Torque; Walking Speed

To analyze the effects of motor learning on knee extension-flexion isokinetic performance in knee osteoarthritis patients.. One hundred and thirty-six middle-aged and older sedentary individuals (111 women, 64.3±9.9 years) with knee osteoarthritis (130 patients with bilateral) and who had never performed isokinetic testing underwent two bilateral knee extension-flexion (concentric-concentric) isokinetic evaluations (5 repetitions) at 60°/sec. The tests were first performed on the dominant leg with 2 min of recovery between test, and following a standardized warm-up that included 3 submaximal isokinetic repetitions. The same procedure was repeated on the non-dominant leg. The peak torque, peak torque adjusted for the body weight, total work, coefficient of variation and agonist/antagonist ratio were compared between tests.. Patients showed significant improvements in test 2 compared to test 1, including higher levels of peak torque, peak torque adjusted for body weight and total work, as well as lower coefficients of variation. The agonist/antagonist relationship did not significantly change between tests. No significant differences were found between the right and left legs for all variables.. The results suggest that performing two tests with a short recovery (2 min) between them could be used to reduce motor learning effects on clinical isokinetic testing of the knee joint in knee osteoarthritis patients.

Topics: Age Factors; Aged; Cross-Sectional Studies; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Practice, Psychological; Statistics, Nonparametric; Time Factors; Torque

Knee Osteoarthritis seems to negatively impact ankle biomechanics. However, the effect of knee osteoarthritis on ankle muscle strength has not been clearly established. This study aimed to evaluate the ankle strength of the plantar flexors and dorsiflexors of patients with knee osteoarthritis in different degrees of severity.. Thirty-seven patients with knee osteoarthritis and 15 controls, subjected to clinical and radiographic analysis, were divided into three groups: control, mild, and moderate knee osteoarthritis. Participants answered a self-reported questionnaire and accomplished a muscle torque assessment of the ankle using the Biodex dynamometer in isometric, concentric and eccentric modes.. The mild osteoarthritis group (peak torque=26.85(SD 3.58)) was significantly weaker than the control (peak torque=41.75(SD 4.42)) in concentric plantar flexion (P<0.05). The control and mild osteoarthritis groups were not significantly different from the moderate osteoarthritis group (peak torque=36.12(SD 4.61)) in concentric plantar flexion. There were no significant differences for dorsiflexion among the groups; however the control and moderate osteoarthritis groups presented large and medium standardized mean differences. The mild osteoarthritis group was significantly lower than the control and moderate osteoarthritis groups in the concentric plantar flexion by concentric dorsiflexion torque ratio.. Ankle function exhibited impairments in patients with knee osteoarthritis, especially in the plantar flexion torque, in which the mild osteoarthritis group was weaker than the control. Interestingly, patients with moderate knee osteoarthritis showed results similar to the control group in plantar flexion torque. The results raise the possibility of a compensatory mechanism of the plantar flexors developed by patients in more advanced degrees to balance other muscle failures.

Topics: Adult; Ankle Joint; Biomechanical Phenomena; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle Strength Dynamometer; Osteoarthritis, Knee; Surveys and Questionnaires; Torque

Knee osteoarthrosis (KOA) is commonly associated with a dysfunction of the quadriceps muscle which contributes to alterations in motor performance. The underlying neuromuscular mechanisms of muscle dysfunction are not fully understood. The main objective of this study was to analyze how KOA affects neuromuscular function of the quadriceps muscle during different contraction intensities.. The following parameters were assessed in 20 patients and 20 healthy controls: (i) joint position sense, i.e. position control (mean absolute error, MAE) at 30° and 50° of knee flexion, (ii) simple reaction time task performance, (iii) isometric maximal voluntary torque (IMVT) and root mean square of the EMG signal (RMS-EMG), (iv) torque control, i.e. accuracy (MAE), absolute fluctuation (standard deviation, SD), relative fluctuation (coefficient of variation, CV) and periodicity (mean frequency, MNF) of the torque signal at 20%, 40% and 60% IMVT, (v) EMG-torque relationship at 20%, 40% and 60% IMVT and (vi) performance fatigability, i.e. time to task failure (TTF) at 40% IMVT.. Compared to the control group, the KOA group displayed: (i) significantly higher MAE of the angle signal at 30° (99.3%; P = 0.027) and 50° (147.9%; P < 0.001), (ii) no significant differences in reaction time, (iii) significantly lower IMVT (-41.6%; P = 0.001) and tendentially lower RMS-EMG of the rectus femoris (-33.7%; P = 0.054), (iv) tendentially higher MAE of the torque signal at 20% IMVT (65.9%; P = 0.068), significantly lower SD of the torque signal at all three torque levels and greater MNF at 60% IMVT (44.8%; P = 0.018), (v) significantly increased RMS-EMG of the vastus lateralis at 20% (70.8%; P = 0.003) and 40% IMVT (33.3%; P = 0.034), significantly lower RMS-EMG of the biceps femoris at 20% (-63.6%; P = 0.044) and 40% IMVT (-41.3%; P = 0.028) and tendentially lower at 60% IMVT (-24.3%; P = 0.075) and (vi) significantly shorter TTF (-51.1%; P = 0.049).. KOA is not only associated with a deterioration of IMVT and neuromuscular activation, but also with an impaired position and torque control at submaximal torque levels, an altered EMG-torque relationship and a higher performance fatigability of the quadriceps muscle. It is recommended that the rehabilitation includes strengthening and fatiguing exercises at maximal and submaximal force levels.

Topics: Aged; Case-Control Studies; Cross-Sectional Studies; Electromyography; Fatigue; Female; Humans; Isometric Contraction; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Proprioception; Psychomotor Performance; Quadriceps Muscle; Reaction Time; Risk Factors; Task Performance and Analysis; Torque

Studies have suggested a compromised postural control in individuals with knee osteoarthritis (OA) evidenced by larger and faster displacement of center of pressure (COP). However, quantification of postural control in the mini-squat posture performed by patients with early knee OA and its relation to muscle strength and self-reported symptoms have not been investigated. The main aim of this cross-sectional, observational, controlled study was to determine whether postural control in the mini-squat posture differs between individuals with early knee OA and a control group (CG) and verify the relation among knee extensor torque (KET) and self-reported physical function, stiffness and pain. Twenty four individuals with knee OA grades I and II (OAG) (mean age: 52.35±5.00) and twenty subjects without knee injuries (CG) (mean age: 51.40±8.07) participated in this study. Participants were assessed in postural control through a force plate (Bertec Mod. USA), which provided information about the anterior-posterior (AP) and medial-lateral (ML) COP displacement during the mini-squat, in isometric, concentric and eccentric knee extensor torque (KET) (90°/s) through an isokinetic dynamometer (BiodexMulti-Joint System3, Biodex Medical Incorporation, New York, NY, USA), and in self-reported symptoms through the WOMAC questionnaire. The main outcomes measured were the AP and ML COP amplitude and velocity of displacement; isometric, concentric, and eccentric KET and self-reported physical function, stiffness and pain. No significant differences were found between groups for postural control (p>0.05). Significant lower eccentric KET (p=0.01) and higher scores for the WOMAC subscales of pain (p=<0.001), stiffness (p=0.001) and physical function (p<0.001) were found for the OAG. Moderate and negative correlations were found between the AP COP amplitude of displacement and physical function (ρ=-0.40, p=0.02). Moderate and negative correlations were observed between the AP COP velocity of displacement and physical function (ρ=0.47, p=0.01) and stiffness (ρ=-0.45, p=0.02). The findings of the present study emphasize the importance of rehabilitation from the early degrees of knee OA to prevent postural instability and the need to include quadriceps muscle strengthening, especially by eccentric contractions. The relationship between the self-reported symptoms and a lower and slower COP displacement suggest that the postural control strategy during tasks with a semi-flexed knee s

Topics: Cross-Sectional Studies; Humans; Isometric Contraction; Knee; Knee Joint; Male; Middle Aged; Movement; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Pain; Postural Balance; Posture; Quadriceps Muscle; Self Report; Torque

Chronic quadriceps dysfunction has been implicated as a contributor to knee osteoarthritis (OA) development after anterior cruciate ligament reconstruction (ACLR). This dysfunction potentially leads to impulsive/high-rate loading during gait, thus accelerating cartilage degradation. The purpose of this study was to examine relationships between several indices of quadriceps function and gait biomechanics linked to knee OA development in individuals with ACLR.. Gait biomechanics and quadriceps function were assessed in 39 individuals with ACLR. Indices of quadriceps function included isometric peak torque and rate of torque development (RTD), isokinetic peak torque and power, and the central activation ratio. Gait biomechanics included the peak vertical ground reaction force and loading rate, and the heel strike transient (HST) magnitude and loading rate.. Isometric peak torque was not associated with any of the gait biomechanical variables. However, greater RTD was associated with lesser peak vertical ground reaction force linear (r = -0.490, P = 0.003) and instantaneous (r = -0.352, P = 0.031) loading rates, as well as a lesser HST magnitude (r = -0.312, P = 0.049) and instantaneous loading rate (r = -0.355, P = 0.029). Greater central activation ratio was associated with greater HST instantaneous (r = 0.311, P = 0.050) and linear (r = 0.328, P = 0.033) loading rates. Isokinetic peak torque and power were not associated with any of the biomechanical variables.. Poor quadriceps function, especially RTD, is associated with gait kinetics linked to cartilage degradation in individuals with ACLR. These results highlight the likely role of chronic quadriceps dysfunction in OA development after ACLR and the need to emphasize improving quadriceps function as a primary rehabilitation goal.

Topics: Adolescent; Adult; Anterior Cruciate Ligament Reconstruction; Biomechanical Phenomena; Cross-Sectional Studies; Female; Gait; Humans; Male; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Torque; Young Adult

Quadriceps muscle weakness is common in knee osteoarthritis (OA). Reasons for weakness may include atrophy, reduction in the muscle fibers number, and changes in the muscle activation. It is uncertain when these muscular changes begin to appear. Therefore, the purpose of this study was to determine whether men with early stages of knee OA already had functional and quadriceps muscle morphologic alterations.. Forty men were divided into two groups: control group (healthy subjects) and OA group (subjects with knee OA). A biopsy of the vastus lateralis muscle was performed for morphometric analysis. Isokinetic evaluation of knee extensor torque, concentric and eccentric (90 and 180 degrees/sec), was performed simultaneously with vastus lateralis electromyographic activity evaluation.. Significant differences were found in knee extensor torque (P < 0.05) and in normalized root mean square (P < 0.01) during the eccentric contractions (both velocities), with higher values for the control group. No differences were found during concentric contractions. The OA group presented greater values of the minimum diameter of type 1 fibers and greater proportion and relative cross-sectional area of type 2b fibers (P < 0.05).. Men with early stages of knee OA do not present alterations of concentric strength but had decreased eccentric strength and morphologic quadriceps muscle changes, indicating neuromuscular adaptations.

Topics: Adult; Aged; Electromyography; Health Status; Humans; Knee Joint; Male; Middle Aged; Muscle Weakness; Osteoarthritis, Knee; Quadriceps Muscle; Range of Motion, Articular; Reference Values; Torque

To determine the extent of asymmetrical deficits in knee extensor and flexor muscles, and to examine whether asymmetrical muscle deficits are associated with mobility limitations in persons with late-stage knee osteoarthritis (OA).. Cross-sectional.. Research laboratory.. A clinical sample (N=56; age range, 50-75y) of eligible persons with late-stage knee OA awaiting knee replacement.. Not applicable.. Knee extensor and flexor power and torque assessed isokinetically; thigh muscle cross-sectional area (CSA) assessed by computed tomography; mobility limitation assessed by walking speed and stair ascension time; and pain assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire.. The asymmetrical deficits in knee extensor and flexor power and torque were between 18% and 29% (P<.001). Regarding the thigh muscle CSA, the asymmetrical deficit was 4% (P<.001). Larger asymmetrical knee extensor power deficits and weaker knee extensor and flexor power on the contralateral side were associated with slower stair ascension times. Moreover, weaker knee extensor and flexor power on the ipsilateral side were associated with slower stair ascension times. Greater knee pain in the OA joint was independently associated with slower stair ascending time in both models.. The knee extensor and flexor muscle power of both the ipsilateral and contralateral sides and the pain in the OA knee were independently associated with stair ascension times. These results highlight the importance of assessing muscle power on both sides and knee pain in the prevention of mobility limitations in patients with knee OA.

Topics: Aged; Cross-Sectional Studies; Female; Gait; Humans; Male; Middle Aged; Mobility Limitation; Muscle Strength; Musculoskeletal Pain; Organ Size; Osteoarthritis, Knee; Quadriceps Muscle; Radiography; Time Factors; Torque

This study aimed to compare muscle activations, co-contraction indices, and the knee adduction moment between static standing yoga postures to identify appropriate exercises for knee osteoarthritis.. Healthy young women (24.4 (5.4) years, 23.1 (3.7) kg/m(2)) participated. Primary outcome variables were electromyographic activations of the vastus lateralis, rectus femoris, vastus medialis, biceps femoris, and semitendinosus; co-contraction between the biceps femoris and rectus femoris, and vastus lateralis and vastus medialis; and knee adduction moments of both legs during six static, standing yoga postures (two squatting postures, two lunging postures, a hamstring stretch, and a single-leg balance posture). A two-factor repeated measures analysis of variance was used to identify differences in muscle amplitudes, co-contractions, and knee adduction moment between postures and legs.. Quadriceps activations were highest during squat and lunge postures (p≤0.001). Hamstring activations were highest during the hamstring stretch (p≤0.003). Squat and lunge postures produced higher co-contraction indices than other postures (p≤0.011). The wide legged squat (Goddess) and lunge with trunk upright (Warrior) produced the lowest knee adduction moments (p≤0.006), while the single-leg balance posture elicited a higher knee adduction moment than all other postures (p<0.05).. Squatting and lunging postures could improve leg strength while potentially minimizing exposure to high knee adduction moments. Future work should evaluate whether these exercises are useful in people with knee osteoarthritis.

Topics: Adolescent; Adult; Biomechanical Phenomena; Electromyography; Exercise; Exercise Therapy; Female; Humans; Isometric Contraction; Knee; Knee Joint; Leg; Muscle, Skeletal; Osteoarthritis, Knee; Postural Balance; Posture; Quadriceps Muscle; Random Allocation; Thigh; Torque; Yoga; Young Adult

Investigations of joint loading in knee osteoarthritis (OA) typically normalize the knee adduction moment to global measures of body size (eg, body mass, height) to allow comparison between individuals. However, such measurements may not reflect knee size. This study used a morphometric measurement of the cartilage surface area on the medial tibial plateau, which better represents medial knee size. This study aimed to determine whether normalizing the peak knee adduction moment and knee adduction moment impulse during gait to the medial tibial bone-cartilage interface could classify radiographic knee OA severity more accurately than traditional normalization techniques. Individuals with mild (N = 22) and severe (N = 17) radiographic knee OA participated. The medial tibial bone-cartilage interface was quantified from magnetic resonance imaging scans. Gait analysis was performed, and the peak knee adduction moment and knee adduction moment impulse were calculated in nonnormalized units and normalized to body mass, body weight × height, and the medial tibial bone-cartilage interface. Receiver operating characteristic curves compared the ability of each knee adduction moment normalization technique to classify participants according to radiographic disease severity. No normalization technique was superior at distinguishing between OA severities. Knee adduction moments normalized to medial knee size were not more sensitive to OA severity.

Topics: Cartilage, Articular; Computer Simulation; Data Interpretation, Statistical; Female; Gait; Humans; Male; Middle Aged; Models, Biological; Organ Size; Osteoarthritis, Knee; Radiographic Image Interpretation, Computer-Assisted; Range of Motion, Articular; Reference Values; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Torque; Weight-Bearing

To identify potential neuromuscular factors associated with dynamic balance in individuals with knee osteoarthritis (OA).. Cross-sectional observational study; backward stepwise multiple linear regression was used to identify factors associated with dynamic balance in 2 statistical models.. University clinical research laboratory.. Individuals aged ≥50 years (N=52) with osteoarthritic changes on radiograph participated.. Not applicable.. Dynamic balance was assessed using the Community Balance and Mobility Scale (CB&M). Potentially modifiable neuromuscular factors associated with dynamic balance were measured, including the sum of concentric and eccentric lower-extremity muscle strength, 2 quadriceps-hamstrings muscle strength ratios, knee joint proprioception (joint position sense), anticipatory postural control velocity, and knee joint range of motion.. The first model for explaining variance in CB&M scores consisted of eccentric lower-extremity muscle strength and knee joint range of motion as factors. The model containing these 2 variables explained 50% of the variance in CB&M scores. The second model adjusted for descriptive variables, including age, body mass index, and knee pain, contained only the neuromuscular variables eccentric lower-extremity muscle strength, and explained 68% of the variance in CB&M scores.. These results suggest that muscle strength and, to a lesser extent, knee joint range of motion are important factors associated with dynamic balance as measured by the CB&M and should be considered in dynamic balance interventions.

Topics: Aged; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Pain Measurement; Postural Balance; Proprioception; Radiography; Range of Motion, Articular; Torque

We examined the effect of knee osteoarthritis on the rate of torque development (RTD) of the knee extensors in older adults with advanced-stage knee osteoarthritis (OA; n=15) and recreationally-active controls (n=15) of similar age, sex and health status, as well as the relationship between RTD and the size and contractility of single muscle fibers. OA participants had lower RTD when expressed in absolute terms (Nm/ms). There were sex differences in peak RTD (P<0.05), with greater RTD in men, but no group by sex interaction effects for any variables. The lower RTD in OA versus controls was not explained by variation between groups in the fiber type admixture of the muscle, and was mitigated when RTD was normalized to peak torque (PT). In knee OA volunteers, we found strong correlations between the RTD expressed relative to PT and the velocity of contraction of single myosin heavy chain (MHC) I and IIA/X muscle fibers (r=0.652 and 0.862; both P<0.05) and power output of MHC I fibers (r=0.642; P<0.05). In controls, RTD relative to PT was related to fiber cross-sectional area of MHC IIA/X fibers (r=0.707; P<0.05), but not measures of single fiber contractile performance. To our knowledge, these results represent the first demonstration that variation in whole muscle contractile kinetics in patients with advanced-stage knee osteoarthritis and healthy older adults is related, in part, to the size and function of single muscle fibers.

Topics: Aged; Biopsy; Case-Control Studies; Female; Humans; Isometric Contraction; Knee Joint; Male; Muscle Fibers, Skeletal; Myosin Heavy Chains; Osteoarthritis, Knee; Torque

It is not clear whether the strength or endurance of thigh muscles (quadriceps and hamstring) is positively or negatively correlated with the adduction moment of osteoarthritic knees. This study therefore assessed the relationships between the strength and endurance of the quadriceps and hamstring muscles and adduction moment in osteoarthritic knees and evaluated predictors of the adduction moment. The study cohort comprised 35 patients with unilateral medial osteoarthritis and varus deformity who were candidates for open wedge osteotomy. The maximal torque (60°/sec) and total work (180°/sec) of the quadriceps and hamstring muscles and knee adduction moment were evaluated using an isokinetic testing device and gait analysis system. The total work of the quadriceps (r = 0.429, P = 0.037) and hamstring (r = 0.426, P = 0.045) muscles at 180°/sec each correlated with knee adduction moment. Preoperative varus deformity was positively correlated with adduction moment (r = 0.421, P = 0.041). Multiple linear regression analysis showed that quadriceps endurance at 180°/sec was the only factor independently associated with adduction moment (β = 0.790, P = 0.032). The adduction moment of osteoarthritic knees correlated with the endurance, but not the strength, of the quadriceps muscle. However, knee adduction moment did not correlate with the strength or endurance of the hamstring muscle.

Topics: Aged; Cross-Sectional Studies; Female; Humans; Knee Joint; Male; Middle Aged; Muscle, Skeletal; Osteoarthritis, Knee; Physical Endurance; Quadriceps Muscle; Range of Motion, Articular; Thigh; Torque

The loads acting in knee joints must be known for improving joint replacement, surgical procedures, physiotherapy, biomechanical computer simulations, and to advise patients with osteoarthritis or fractures about what activities to avoid. Such data would also allow verification of test standards for knee implants. This work analyzes data from 8 subjects with instrumented knee implants, which allowed measuring the contact forces and moments acting in the joint. The implants were powered inductively and the loads transmitted at radio frequency. The time courses of forces and moments during walking, stair climbing, and 6 more activities were averaged for subjects with I) average body weight and average load levels and II) high body weight and high load levels. During all investigated activities except jogging, the high force levels reached 3,372-4,218N. During slow jogging, they were up to 5,165N. The peak torque around the implant stem during walking was 10.5 Nm, which was higher than during all other activities including jogging. The transverse forces and the moments varied greatly between the subjects, especially during non-cyclic activities. The high load levels measured were mostly above those defined in the wear test ISO 14243. The loads defined in the ISO test standard should be adapted to the levels reported here. The new data will allow realistic investigations and improvements of joint replacement, surgical procedures for tendon repair, treatment of fractures, and others. Computer models of the load conditions in the lower extremities will become more realistic if the new data is used as a gold standard. However, due to the extreme individual variations of some load components, even the reported average load profiles can most likely not explain every failure of an implant or a surgical procedure.

Topics: Activities of Daily Living; Aged; Arthroplasty, Replacement, Knee; Biomechanical Phenomena; Body Weight; Female; Humans; Jogging; Knee Joint; Knee Prosthesis; Male; Middle Aged; Osteoarthritis, Knee; Reference Standards; Reference Values; Stress, Mechanical; Torque; Walking

The long-term consequences on knee muscle strength some decades after rupture of the anterior cruciate ligament (ACL) are not established. The aims of our study were to examine peak torque more than 20 years after ACL injury and to compare their knee muscle strength to that of healthy controls. We tested 70 individuals with unilateral ACL injury 23 ± 2 years after injury, whereof 33 (21 men) were treated with physiotherapy in combination with ACL reconstruction (ACLR ) and 37 (23 men) with physiotherapy alone (ACLPT ). These were compared with 33 age- and gender-matched controls (21 men). A Kin-Com(®) dynamometer (90°/s) was used to measure peak torque in knee flexion and extension in both concentric and eccentric contractions. Knee extension peak torque, concentric and eccentric, was ∼10% lower for the injured leg compared with the non-injured leg for both ACLR (P < 0.001; P < 0.001) and ACLPT (P = 0.007; P = 0.002). The ACLPT group also showed reduced eccentric knee flexion torque of the injured leg (P = 0.008). The strength of the non-injured leg in both ACL groups was equal to that of controls. No difference was seen for those with no-or-low degree of knee osteoarthritis compared to those with moderate-to-high degree of osteoarthritis. ACL injury may lead to a persistent reduction of peak torque in the injured leg, which needs to be considered across the lifespan.

Topics: Adult; Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Contraction; Muscle Strength; Muscle Strength Dynamometer; Osteoarthritis, Knee; Physical Therapy Modalities; Quadriceps Muscle; Radiography; Time Factors; Torque

It has been suggested to use gait modifications in the retraining of patients with knee osteoarthritis (OA), in order to reduce the external knee adduction moment (KAdM). This study focused on the effect of walking speed, foot position and trunk sway, and on the 3D knee moments. Gait analyses of fourteen healthy volunteers were performed in a gait laboratory. Subjects walked at three different speeds in their normal gait pattern, as well as with toe-in and toe-out gait and with medio-lateral trunk sway at a self-selected speed. Fast walking speed increased the KAdM (17-30%) and flexion moment (32%). A slower walking speed did not decrease the KAdM. Toe-in mainly decreased the KAdM (45%) and the transverse moment (38%) during early stance. Toe-out decreased the KAdM during late stance (56%), but increased the KAdM during early stance and midstance (21-24%), due to decreased endorotation of the hip with knee flexion. Trunk sway decreased the KAdM during early stance and midstance (31-33%). Gait modifications mainly affected the KAdM, but changes in sagittal and transverse knee moments and kinematics were also observed. This indicates that, when estimating knee load, taking only the frontal plane kinetics into consideration may lead to erroneous simplifications. No conclusive beneficial effects were found in any of the gait modifications throughout the entire stance phase.

Topics: Adult; Biomechanical Phenomena; Female; Gait; Humans; Kinesthesis; Knee Joint; Male; Osteoarthritis, Knee; Range of Motion, Articular; Reaction Time; Reference Values; Torque; Volition; Weight-Bearing; Young Adult

Intraoperative soft tissue tension can significantly impact the range of motion following total knee arthroplasty (TKA). However, the level of impact remains unclear. The purpose of this study was to investigate the relationship between intraoperative soft tissue tension and postoperative range of motion.. This retrospective study included 504 patients operated with posterior stabilized TKA. During surgery, we adjusted the soft tissue tension from 80 to 160 N for both flexion and extension with the tensor/balancer device and torque driver. Patients were grouped into three categories based on intraoperative soft tissue tension and analyzed with the 1-year postoperative range of motion using one-way analysis of variance (ANOVA). In addition, Pearson's correlation coefficients were determined to assess the association between intraoperative soft tissue tension and postoperative range of motion.. The absolute tension value at 90° flexion did not affect the postoperative flexion angle (p = 0.61). The absolute tension value at 0° extension did not affect the postoperative extension angle (p = 0.91). Likewise, the difference of tension between flexion and extension did not affect the postoperative flexion angle (p = 0.86). All comparisons did not have the differences in sex, height, weight, body mass index, diagnosis and preoperative range of motion between three groups. No significant correlation was found in each comparison (r = 0.078, r = 0.031, r = -0.052, respectively).. We did not observe a correlation between intraoperative soft tissue tension adjusted from 80 to 160 N and 1-year postoperative range of motion in posterior stabilized TKA.

Topics: Aged; Arthroplasty, Replacement, Knee; Female; Humans; Intraoperative Period; Male; Osteoarthritis, Knee; Postoperative Period; Range of Motion, Articular; Retrospective Studies; Torque

To examine the relationship between knee osteoarthritis (OA) and muscle parameters in a biracial cohort of older adults.. Participants in the Health, Aging and Body Composition Study (n = 858) were included in this cross-sectional analysis. Computed tomography was used to measure muscle area, and quadriceps strength was measured isokinetically. Muscle quality (specific torque) was defined as strength per unit of muscle area for both the entire thigh and quadriceps. Knee OA was assessed based on radiographic features and knee pain. We compared muscle parameters between those with and without radiographic knee OA (+RKOA group and -RKOA group, respectively) and among 4 groups defined by +RKOA and -RKOA with and without pain.. The mean ± SD age was 73.5 ± 2.9 years and the mean ± SD body mass index (BMI) was 27.9 ± 4.8 kg/m(2) . Fifty-eight percent of participants were women and 44% were African American. Compared to the -RKOA participants, +RKOA participants had a higher BMI (30.2 versus 26.8 kg/m(2)), larger thigh muscles (117.9 versus 108.9 cm(2)), and a greater amount of intermuscular fat (12.5 versus 9.9 cm(2) ; all P < 0.0001). In adjusted models, the +RKOA participants had significantly lower specific torque (P < 0.001), indicating poorer muscle quality, than -RKOA participants, but there was no difference between groups in quadriceps specific torque. The +RKOA without pain (P < 0.05) and the +RKOA with pain (P < 0.001) participants had lower specific torque compared to the -RKOA without pain group. There were no significant differences in quadriceps specific torque among groups.. Muscle quality was significantly poorer in participants with RKOA regardless of pain status. Future studies should address how lifestyle interventions might affect muscle quality and progression of knee OA.

Topics: Adiposity; Age Factors; Aged; Analysis of Variance; Arthralgia; Biomechanical Phenomena; Black or African American; Body Mass Index; Case-Control Studies; Cross-Sectional Studies; Disease Progression; Female; Humans; Linear Models; Male; Muscle Strength; Muscle Weakness; Organ Size; Osteoarthritis, Knee; Pain Measurement; Pennsylvania; Quadriceps Muscle; Risk Assessment; Risk Factors; Sex Factors; Tennessee; Tomography, X-Ray Computed; Torque; White People

The peak knee adduction moment is a valid proxy for medial knee joint loading. However as it only measures load at one instance of stance, knee adduction moment impulse, a measure that takes into account both the magnitude and duration of the stance phase, may provide more comprehensive information. This study directly compared the abilities of peak knee adduction moment and knee adduction moment impulse to distinguish between knee osteoarthritis severities.. 169 participants with medial knee osteoarthritis completed radiographic and magnetic resonance imaging, the Western Ontario and McMaster Universities Arthritis Index to assess pain and a three-dimensional gait analysis. Participants were classified using four dichotomous classifications: Kellgren-Lawrence grading, alignment, medial tibiofemoral bone marrow lesions, and pain.. When using Kellgren-Lawrence grade and alignment classifications, the area under the receiver operator curves were significantly greater for knee adduction moment impulse than for peak knee adduction moment. Based on analysis of covariance, knee adduction moment impulse was significantly different between Kellgren-Lawrence grade and alignment groups while peak knee adduction moment was not significantly different. Both peak knee adduction moment and knee adduction moment impulse distinguished between bone marrow lesion severities while neither measure was significantly different between pain severity groups.. Findings suggest knee adduction moment impulse is more sensitive at distinguishing between disease severities and may provide more comprehensive information on medial knee joint loading. Future studies investigating biomechanics of knee osteoarthritis should include knee adduction moment impulse in conjunction with peak knee adduction moment.

Topics: Aged; Female; Humans; Image Interpretation, Computer-Assisted; Knee Joint; Magnetic Resonance Imaging; Male; Middle Aged; Osteoarthritis, Knee; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Torque

Table tennis involves adoption of the semi-flexed knee and asymmetrical torsional trunk movements creating rotational torques on the knee joint which may predispose players to osteoarthritis (OA) of the knee. This study aims to compare radiographic signs of knee OA and associated functional levels in ex-elite male table tennis players and control subjects.. Study participants were 22 ex-elite male table tennis players (mean age 56.64 ± 5.17 years) with 10 years of involvement at the professional level and 22 non-athletic males (mean age 55.63 ± 4.08 years) recruited from the general population. A set of three radiographs taken from each knee were evaluated by an experienced radiologist using the Kellgren and Lawrence (KL) scale (0-4) to determine radiographic levels of OA severity. The intercondylar distance was taken as a measure of lower limb angulation. Participants also completed the pain, stiffness, and physical function categories of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) 3.1 questionnaire.. The results showed 78.3% of the ex-elite table tennis players and 36.3% of controls had varying signs of radiographic knee OA with a significant difference in the prevalence levels of definite radiographic OA (KL scale > 2) found between the two groups (P ≤ 0.001). Based on the WOMAC scores, 68.2% of the ex-elite table tennis players reported symptoms of knee pain compared with 27.3% of the controls (p = 0.02) though no significant differences were identified in the mean physical function or stiffness scores between the two groups. In terms of knee alignment, 73.7% of the ex-elite athletes and 32% of the control group had signs of altered lower limb alignment (genu varum) (p = 0.01). Statistical differences were found in subjects categorized as having radiographic signs of OA and altered lower limb alignment (p = 0.03).. Ex-elite table tennis players were found to have increased levels of radiological signs of OA in the knee joint though this did not transpire through to altered levels of physical disability or knee stiffness in these players when compared with subjects from the general population suggesting that function in these players is not severely impacted upon.

Topics: Biomechanical Phenomena; Case-Control Studies; Chi-Square Distribution; Disability Evaluation; Humans; Iran; Knee Joint; Male; Middle Aged; Osteoarthritis, Knee; Pain Measurement; Racquet Sports; Radiography; Range of Motion, Articular; Risk Assessment; Risk Factors; Rotation; Severity of Illness Index; Surveys and Questionnaires; Torque; Weight-Bearing

The aim of this study was to check whether there was a correlation between the value of the maximum developed torque of the quadriceps femoris muscle and subjective evaluation of a patient's pain which is measured by the VAS. Also evaluated were changes in the muscle torque value and KSS scale over time. For examining patient's condition use was made of a KSS scale (knee score: pain, range of motion, stability of joint and limb axis) before the surgery and in weeks 6 and 12, as well as 6 months after surgery. It was found to be constantly improving in comparison with the condition before the surgery. This is confirmed by a significant statistical value difference of KSS scale. The surgery substantially increases the quality of live and function recurrence.

Topics: Aged; Biomechanical Phenomena; Female; Humans; Isometric Contraction; Male; Osteoarthritis, Knee; Pain Measurement; Quadriceps Muscle; Torque

Osteoarthritis affects the whole body, thus biomechanical effects on other joints should be considered. Unloading knee braces could be effective for knee osteoarthritis, but their effects on the contralateral knee and bilateral hip joints remain unknown. This study investigated the effects of bracing on the kinematics and kinetics of involved and contralateral joints during gait.. Nineteen patients with medial compartment knee osteoarthritis were analysed. Kinematics and kinetics of the knee and hip joints in frontal and sagittal planes were measured during walking without and with bracing on the more symptomatic knee.. The ipsilateral hip in the braced condition showed a lower adduction angle by an average of 2.58° (range, 1.05°-4.16°) during 1%-49% of the stance phase, and a lower abduction moment at the second peak during the stance phase than the hip in the unbraced condition (P<0.05 and P<0.005, respectively). With bracing, the contralateral hip showed a more marked peak extension moment and lower abduction moment at the first peak (P<0.05), and the contralateral knee adduction angle increased by an average of 0.32° (range, 0.21°-0.45°) during 46%-55% of the stance phase (P<0.05), compared to no bracing.. Unloading bracing modified the contralateral knee adduction angle pattern at a specific time point during gait. It also affected the frontal plane on the ipsilateral hip and the frontal and sagittal planes on the contralateral hip joint. Consideration should be provided to other joints when treating knee osteoarthritis.

Topics: Aged; Braces; Female; Hip Joint; Humans; Knee Joint; Male; Osteoarthritis, Knee; Range of Motion, Articular; Torque; Treatment Outcome; Weight-Bearing

The goal of this study was to determine if increasing strength in primary knee extensors and flexors would directly affect net knee joint moments during a common functional task in persons with knee osteoarthritis.. An exploratory single sample clinical trial with pre-post treatment measures was used to study volunteers with clinical diagnosis of mild knee osteoarthritis (OA) in one knee. Subjects participated in an individually supervised training program 3 times a week for eight weeks consisting of progressive resistive exercises for knee extensors and knee flexors. Pre and post training outcome assessments included: 1. Net internal knee joint moments, 2. Electromyography of primary knee extensors and flexors, and 3. Self-report measures of knee pain and function. The distribution of lower extremity joint moments as a percent of the total support moment was also investigated.. Pain, symptoms, activities of daily life, quality of life, stiffness, and function scores showed significant improvement following strength training. Knee internal valgus and hip internal rotation moments showed increasing but non-statistically significant changes post-training. There were no significant differences in muscle co-contraction activation of the Quadriceps and Hamstrings.. While exercise continues to be an important element of OA management, the results of this study suggest improvements in function, pain, and other symptoms, as a result of strength training may not be causally related to specific biomechanical changes in net joint moments.

Topics: Adult; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Contraction; Muscle, Skeletal; Osteoarthritis, Knee; Range of Motion, Articular; Resistance Training; Torque; Treatment Outcome

Topics: Biomechanical Phenomena; Humans; Orthotic Devices; Osteoarthritis, Knee; Shoes; Torque

Maximal isometric quadriceps strength deficits have been widely reported in studies of knee osteoarthritis (OA), however little is known about the effect of osteoarthritis knee pain on submaximal quadriceps neuromuscular function. The purpose of this study was to measure vastus medialis motor unit (MU) properties in participants with knee OA, during submaximal isometric contractions.. Vastus medialis motor unit potential (MUP) parameters were assessed in 8 patients with knee OA and 8 healthy, sex and age-matched controls during submaximal isometric contractions (20% of maximum isometric torque). Unpaired t-tests were used to compare groups for demographic and muscle parameters.. Maximum knee extension torque was ~22% lower in the OA group, a difference that was not statistically significantly (p = 0.11). During submaximal contractions, size related parameters of the needle MUPs (e.g. negative peak duration and amplitude-to-area ratio) were greater in the OA group (p < 0.05), with a rightward shift in the frequency distribution of surface MUP negative peak amplitude. MUP firing rates were significantly lower in the OA group (p < 0.05).. Changes in MU recruitment and rate coding strategies in OA may reflect a chronic reinnervation process or a compensatory strategy in the presence of chronic knee pain associated with OA.

Topics: Action Potentials; Electromyography; Female; Humans; Isometric Contraction; Knee Joint; Male; Middle Aged; Motor Neurons; Neural Conduction; Osteoarthritis, Knee; Pain; Quadriceps Muscle; Range of Motion, Articular; Recruitment, Neurophysiological; Torque

A consequence of knee joint osteoarthritis (OA) is an inability to fully activate the quadriceps muscles, a problem termed arthrogenic muscle inhibition (AMI). AMI leads to marked quadriceps weakness that impairs physical function and may hasten disease progression. The purpose of the present study was to determine whether γ-loop dysfunction contributes to AMI in people with knee joint OA.. Fifteen subjects with knee joint OA and 15 controls with no history of knee joint pathology participated in this study. Quadriceps and hamstrings peak isometric torque (Nm) and electromyography (EMG) amplitude were collected before and after 20 minutes of 50 Hz vibration applied to the infrapatellar tendon. Between-group differences in pre-vibration torque were analysed using a one-way analysis of covariance, with age, gender and body mass (kg) as the covariates. If the γ-loop is intact, vibration should decrease torque and EMG levels in the target muscle; if dysfunctional, then torque and EMG levels should not change following vibration. One-sample t tests were thus undertaken to analyse whether percentage changes in torque and EMG differed from zero after vibration in each group. In addition, analyses of covariance were utilised to analyse between-group differences in the percentage changes in torque and EMG following vibration.. Pre-vibration quadriceps torque was significantly lower in the OA group compared with the control group (P = 0.005). Following tendon vibration, quadriceps torque (P < 0.001) and EMG amplitude (P ≤0.001) decreased significantly in the control group but did not change in the OA group (all P > 0.299). Hamstrings torque and EMG amplitude were unchanged in both groups (all P > 0.204). The vibration-induced changes in quadriceps torque and EMG were significantly different between the OA and control groups (all P < 0.011). No between-group differences were observed for the change in hamstrings torque or EMG (all P > 0.554).. γ-loop dysfunction may contribute to AMI in individuals with knee joint OA, partially explaining the marked quadriceps weakness and atrophy that is often observed in this population.

Topics: Aged; Biomechanical Phenomena; Electromyography; Female; Humans; Knee Joint; Male; Middle Aged; Muscle Weakness; Osteoarthritis, Knee; Quadriceps Muscle; Torque; Vibration

Quadriceps dysfunction, specifically weakness and central activation failure (CAF), has been implicated in the development and progression of knee osteoarthritis (OA), though few data are available to confirm its presence in early OA. The purpose of this study was to determine the presence and magnitude of quadriceps dysfunction in those with and without early knee OA. Thirty-five female volunteers were classified into two groups, OA (n=22) and control (n=13), based on the presence [Kellgren-Lawrence (K-L) grade 2] or absence (K-L grade 0-1) of mild OA, respectively. Isometric quadriceps strength and central activation ratio (CAR) were assessed and compared between groups utilizing a one-way ANOVA. Frequency statistics and Fisher's exact test were used to compare the percentage of women with and without CAF between groups. Quadriceps strength (control: 1.47+/-0.62 Nm/kg; OA: 1.30+/-0.62 Nm/kg; p=0.45) was not significantly different for women with and without mild OA. Further, the CAR (control: 0.91+/-0.07; OA: 0.87+/-0.12; p=0.19) did not differ between groups; however, women in both groups presented with CAF (control: 54%; OA: 73%; p=0.29). Our results suggest that the women with mild osteoarthritis do not present with quadriceps dysfunction.

Topics: Disability Evaluation; Disease Progression; Female; Humans; Knee Joint; Middle Aged; Models, Biological; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Radiography; Severity of Illness Index; Torque; Weight-Bearing

To compare the effects of an acute stretching intervention on knee extension range of motion, passive resistive torque and stiffness in subjects with osteoarthritis of the knee, and to compare these variables with subjects without osteoarthritis.. Cross-sectional experimental study.. Human performance laboratory.. A total of 55 participants were recruited: 28 subjects (males and females) with osteoarthritis of the knee joint and 27 subjects of a similar age without osteoarthritis of the knee joint.. Using the Kincom dynamometer, three 60-second stretches with 60seconds of rest between stretches were applied to the hamstring muscle group.. Peak knee extension range of motion, peak passive torque and stiffness in the final 10% of knee extension range of motion.. A significant (P<0.05) increase in knee extension range of motion, peak passive torque and stiffness was observed in both groups. For knee extension range of motion, the mean difference for the osteoarthritis group and non-osteoarthritis group was 4.9 degrees [95% confidence interval (CI) 0.9 to 8.5] and 4.4 degrees (95% CI 1.8 to 6.8), respectively. For peak passive torque, the mean difference in the osteoarthritis group and the non-osteoarthritis group was 4.4Nm (95% CI 0.8 to 6.9) and 1.0Nm (95% CI -1.4 to 3.5), respectively. For stiffness in the final 10% of knee extension range of motion, the mean difference for the osteoarthritis group and the non-osteoarthritis group was 0.19Nm/degree (95% CI 0.08 to 0.3) and 0.04Nm/degree (95% CI -0.05 to 0.1), respectively. Stiffness in the final 10% of knee extension range of motion was significantly higher in the osteoarthritis group compared with the non-osteoarthritis group after stretching.. Elderly individuals with and without osteoarthritis of the knee are able to demonstrate immediate beneficial adaptations to a stretching intervention. This is important as stretching is often used in preparation for exercise programmes.

Topics: Aged; Cross-Sectional Studies; Female; Humans; Knee; Male; Middle Aged; Muscle Stretching Exercises; Muscle, Skeletal; Osteoarthritis, Knee; Pliability; Range of Motion, Articular; Thigh; Torque

Quadriceps muscle weakness and the underlying neuromuscular deficits have been increasingly studied over the last few years in patients with knee osteoarthritis, but the applied methodologies have never been validated for this specific population. The aim of this study was to investigate test-retest reliability of several quadriceps muscle function outcomes in patients with knee osteoarthritis both before and after knee arthroplasty surgery. Ten preoperative and 20 postoperative patients participated in two identical testing sessions. A series of voluntary and/or electrically stimulated contractions of the involved quadriceps with concomitant torque and electromyographic recordings were used to characterize muscle strength, muscle activation and muscle contraction properties. Vastus lateralis morphology (thickness and fascicle pennation angle) was also assessed using ultrasonography. Overall, good reliability scores were observed for the majority of the 13 assessed variables (nine variables with intraclass correlation coefficients >0.75, 12 variables with coefficients of variation <15%). The most reliable testing protocol for patients with knee osteoarthritis would entail the assessment of (1) isometric maximal voluntary torque for evaluating muscle strength, with (2) simultaneous vastus lateralis electromyographic activity for evaluating muscle activation, (3) potentiated (resting) doublet peak torque for evaluating muscle contractility, and (4) vastus lateralis thickness for evaluating muscle size.

Topics: Arthroplasty, Replacement, Knee; Electric Stimulation; Electromyography; Humans; Middle Aged; Muscle Contraction; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Reproducibility of Results; Torque

To compare the strength of the hip musculature in people with symptomatic medial knee osteoarthritis (OA) with asymptomatic controls.. Eighty-nine people with knee OA and 23 controls age >50 years were recruited from the community. The maximal isometric strength (torque relative to body mass) of the hip abductors, adductors, flexors, extensors, and internal and external rotators was evaluated using hand-held dynamometry or a customized force transducer apparatus. Univariate linear models with age and sex included as covariates were used to compare muscle strength between groups.. In people with knee OA, significant strength deficits were evident for all hip muscle groups evaluated (P < 0.05). Compared with controls, strength deficits ranged from 16% (hip extensors) to 27% (hip external rotators) after accounting for differences in sex and age between groups.. People with knee OA demonstrate significant weakness of the hip musculature compared with asymptomatic controls. It is not clear if hip muscle weakness precedes the onset of knee OA or occurs as a consequence of disease. Findings from this study support the inclusion of hip strengthening exercises in rehabilitation programs.

Topics: Aged; Case-Control Studies; Exercise; Exercise Therapy; Female; Hip; Humans; Male; Middle Aged; Muscle Strength; Muscle Weakness; Osteoarthritis, Knee; Pain; Torque

To examine the test-retest reliability and quantify the minimal detectable change (MDC) in quadriceps strength and voluntary activation in patients with knee osteoarthritis (OA).. Repeated measures over a 1-week interval.. Tertiary care center.. A convenience sample of patients (N=20) diagnosed with knee OA.. Isokinetic and isometric quadriceps strength testing and voluntary quadriceps activation testing using interpolated twitch technique.. Peak isokinetic and isometric knee extension torque (Nm) and percentage of voluntary quadriceps activation (%).. The mean differences with 95% confidence intervals between the 2 test sessions for quadriceps isokinetic strength, isometric strength, and percent of voluntary activation were -4.34Nm (-14.01 to 5.34Nm), 1.56Nm (-5.56 to 8.68Nm), and 1.34% (-.53 to 3.22%), respectively. The intraclass correlation coefficients for all measures ranged from .93 to .98. The standard errors of measurement (SEMs) for quadriceps isokinetic and isometric strength were 14.57Nm and 10.76Nm, respectively. The SEM for percentage of voluntary activation was 2.84%. Based on these values, the MDCs were 33.90Nm, 25.02Nm, and 6.60% for quadriceps isokinetic strength, isometric strength, and percentage of voluntary activation, respectively.. Maximal quadriceps isokinetic strength, isometric strength, and percentage of voluntary activation measures demonstrate excellent test-retest reliability in patients with knee OA. In addition to research applications, the present findings suggest these measures are appropriate for use when evaluating change in neuromuscular function of the quadriceps in individual patients.

Topics: Disability Evaluation; Female; Humans; Isometric Contraction; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Reproducibility of Results; Torque

To evaluate the difference in isokinetic strength of hip muscles between patients with knee osteoarthritis (OA) and matched healthy controls, and to establish the correlation between this isokinetic strength and pain and function in patients with knee OA.. 25 patients with a diagnosis of unilateral knee OA, 25 patients with bilateral knee OA, and 50 matched controls were evaluated using the visual analog scale for pain, knee Lequesne index, Western Ontario and McMaster Universities questionnaire and an isokinetic test.. The groups were matched for age, gender and body mass index. The results of the isokinetic test revealed lower peak torque of the hip in patients with OA of the knee than in the control group for all movements studied. Strong correlations were found between the peak torque, visual analog scale and function.. Patients with OA of the knee exhibit lower isokinetic strength in the hip muscles than healthy control subjects. Strengthening the muscles surrounding the hip joint may help to decrease pain in people with knee OA. Some correlations between pain/function and peak torque were found.

Topics: Adult; Body Mass Index; Case-Control Studies; Exercise Test; Female; Hip; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Osteoarthritis, Knee; Pain; Torque

To examine whether pretreatment magnitude of quadriceps activation (QA) helps predict changes in quadriceps strength after exercise therapy in subjects with knee osteoarthritis (OA). We hypothesized that subjects with lower magnitudes of QA (greater failure of muscle activation) would have smaller gains in strength compared with those with higher magnitudes of QA following exercise therapy.. One hundred eleven subjects with knee OA (70 women) participated. Baseline measures included demographic information, quadriceps muscle strength, and QA using a burst-superimposition isometric torque test. Following baseline testing, subjects underwent a 6-week supervised exercise program designed to improve strength, range of motion, balance and agility, and physical function. On completion of the program, quadriceps strength and QA were reassessed. Multiple regression analysis was used to determine whether baseline QA predicted quadriceps strength scores at the 2-month followup.. Bivariate correlations demonstrated that baseline QA was significantly associated with quadriceps strength at baseline (rho = 0.30, P < 0.01) and 2-month followup (rho = 0.23, P = 0.01). Greater magnitude of baseline QA correlated with higher strength. While controlling for baseline quadriceps strength and type of exercise therapy, the level of QA did not predict quadriceps strength at the 2-month followup (beta = -0.04, P = 0.18).. Baseline QA did not predict changes in quadriceps strength following exercise therapy. Measurement of QA using the central activation ratio method does not appear to be helpful in identifying subjects with knee OA who will have difficulty improving quadriceps strength with exercise therapy.

Topics: Adult; Aged; Aged, 80 and over; Exercise Therapy; Female; Follow-Up Studies; Humans; Knee Joint; Longitudinal Studies; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Quadriceps Muscle; Randomized Controlled Trials as Topic; Range of Motion, Articular; Regression Analysis; Torque; Treatment Outcome

The purpose of this study was to evaluate the effectiveness of variable-stiffness shoes in lowering the peak external knee adduction moment during walking in subjects with symptomatic medial compartment knee osteoarthritis. The influence on other lower extremity joints was also investigated. The following hypotheses were tested: (1) variable-stiffness shoes will lower the knee adduction moment in the symptomatic knee compared to control shoes; (2) reductions in knee adduction moment will be greater at faster speeds; (3) subjects with higher initial knee adduction moments in control shoes will have greater reductions in knee adduction moment with the intervention shoes; and (4) variable-stiffness shoes will cause secondary changes in the hip and ankle frontal plane moments. Seventy-nine individuals were tested at self-selected slow, normal, and fast speeds with a constant-stiffness control shoe and a variable-stiffness intervention shoe. Peak moments for each condition were assessed using a motion capture system and force plate. The intervention shoes reduced the peak knee adduction moment compared to control at all walking speeds, and reductions increased with increasing walking speed. The magnitude of the knee adduction moment prior to intervention explained only 11.9% of the variance in the absolute change in maximum knee adduction moment. Secondary changes in frontal plane moments showed primarily reductions in other lower extremity joints. This study showed that the variable-stiffness shoe reduced the knee adduction moment in subjects with medial compartment knee osteoarthritis without the discomfort of a fixed wedge or overloading other joints, and thus can potentially slow the progression of knee osteoarthritis.

Topics: Computer Simulation; Elasticity; Equipment Failure Analysis; Female; Gait Disorders, Neurologic; Humans; Knee Joint; Male; Middle Aged; Models, Biological; Orthotic Devices; Osteoarthritis, Knee; Prosthesis Design; Shoes; Torque; Treatment Outcome

Patients with knee osteoarthritis have both poor strength and endurance of their quadriceps muscles. It is possible to assess muscle fatigue by monitoring frequency spectrum using electromyography (EMG). This study used the closed kinetic chain approach to muscle assessment. Fifty-five subjects with knee osteoarthritis were examined twice within 1 week. To test maximum voluntary isometric contraction into extension an isokinetic dynamometer, with a closed kinetic chain "leg press" attachment was used. EMG assessment of signal median frequency was done by measuring median frequency shift associated with fatiguing of muscle during a 60s isometric contraction at 60% of maximum isometric contraction. Intra-class correlation coefficients with 95% confidence intervals, standard errors of measurement and smallest detectable differences were calculated. Results showed the reliability of the maximum voluntary isometric contraction extension strength test was ICC 0.99 and SEM 3.95Nm. The initial median frequency indices also demonstrated excellent ICC and SEM statistics (ICC 0.84-0.91, SEM 9.2-11Hz) for the three heads of the quadriceps; however, the fatigue slopes for all three muscles were unreliable with poor ICCs (0.04-0.72) and SDD values (2207-4000%). The assessment of peak muscle torque using a closed kinetic chain isometric technique is reliable, as is the determination of median frequency values for the quadriceps. Error for the assessment of fatigue was of an unacceptable scale. While the use of a closed kinetic chain leg press technique provides a reliable measurement of lower limb strength, EMG power spectrum decrease during an isometric contraction is of little value.

Topics: Electromyography; Female; Humans; Isometric Contraction; Male; Middle Aged; Muscle Fatigue; Observer Variation; Osteoarthritis, Knee; Quadriceps Muscle; Reproducibility of Results; Torque

The significance of achievement of soft tissue balancing in total knee arthroplasty is well recognized. There are few reports dealing with soft tissue tension in total knee arthroplasty. It is expected that the soft tissue tension will affect post-operative results such as postoperative ROM and stability. The purpose of this study was to evaluate tension properties of soft tissue complex of osteoarthritic knee in total knee arthroplasty. Sixty osteoarthritic knees that underwent primary total knee arthroplasty were investigated with a balancer and torque driver specially developed and adapted for this study. We gradually opened the extension and flexion space and measured the force to open it. We created a force-displacement curve in each case. Inclination of the curve indicated stiffness. We examined the stiffness average of all cases every 10 N. The stiffness was 8.9 and 8.5 N/mm (extension, flexion) in soft tissue tension of 60 N and 26.6 and 21.4 N/mm in 180 N. The stiffness became larger with an increase of soft tissue tension, and the stiffness of extension is significantly larger than that of flexion in each tension except for 60 N. Tension properties of soft tissue complex reveal that soft tissue can be easily extended in low soft tissue tension, and hardly extended in high tension.

Topics: Aged; Aged, 80 and over; Arthroplasty, Replacement, Knee; Elasticity; Female; Humans; Knee Joint; Male; Middle Aged; Osteoarthritis, Knee; Torque; Weights and Measures

Altered gait kinematics and kinetics are observed in patients with medial compartment knee osteoarthritis. Although various kinematic adaptations are proposed to be compensatory mechanisms that unload the knee, the nature of these mechanisms is presently unclear. We hypothesized that an increased toe-out angle during early stance phase of gait shifts load away from the knee medial compartment, quantified as the external adduction moment about the knee. Specifically, we hypothesized that by externally rotating the lower limb anatomy, primarily about the hip joint, toe-out gait alters the lengths of ground reaction force lever arms acting about the knee joint in the frontal and sagittal planes and transforms a portion of knee adduction moment into flexion moment. To test this hypothesis, gait data from 180 subjects diagnosed with medial compartment knee osteoarthritis were examined using two frames of reference. The first frame was attached to the tibia (reporting actual toe-out) and the second frame was attached to the laboratory (simulating no-toe-out). Four measures were compared within subjects in both frames of reference: the lengths of ground reaction force lever arms acting about the knee joint in the frontal and sagittal planes, and the adduction and flexion components of the external knee moment. The mean toe-out angle was 11.4 degrees (S.D. 7.8 degrees , range -2.2 degrees to 28.4 degrees ). Toe-out resulted in significant reductions in the frontal plane lever arm (-6.7%) and the adduction moment (-11.7%) in early stance phase when compared to the simulated no-toe-out values. These reductions were coincident with significant increases in the sagittal plane lever arm (+33.7%) and flexion moment (+25.0%). Peak adduction lever arm and moment were also reduced significantly in late stance phase (by -22.9% and -34.4%, respectively) without a corresponding increase in sagittal plane lever arm or flexion moment. These results indicate that toe-out gait in patients with medial compartment knee osteoarthritis transforms a portion of the adduction moment into flexion moment in early stance phase, suggesting that load is partially shifted away from the medial compartment to other structures.

Topics: Adolescent; Adult; Computer Simulation; Female; Gait; Humans; Knee Joint; Male; Middle Aged; Models, Biological; Osteoarthritis, Knee; Range of Motion, Articular; Toes; Torque

Changes in footwear and foot orthotic devices have been shown to significantly alter knee joint torques thought to be relevant to the progression if not the development of knee osteoarthritis (OA) in the medial tibiofemoral compartment. The purpose of this study was to determine if commonly prescribed arch support cushions promote a medial force bias during gait similar to medial-wedged orthotics, thereby increasing knee varus torque during both walking and running.. Twenty-two healthy, physically active young adults (age, 29.2 +/- 5.1 yr) were analyzed at their self-selected walking and running speeds in control shoes with and without arch support cushions. Three-dimensional motion capture data were collected in synchrony with ground reaction force (GRF) data collected from an instrumented treadmill. Peak external knee varus torque during walking and running were calculated through a full inverse dynamic model and compared.. Peak knee varus torque was statistically significantly increased by 6% (0.01 +/- 0.02 N.m.(kg.m)(-1)) in late stance during walking and by 4% (0.03 +/- 0.03 N.m.(kg.m)(-1)) during running with the addition of arch support cushions.. The addition of material under the medial aspect of the foot by way of a flexible arch support promotes a medial force bias during walking and running, significantly increasing knee varus torque. These findings suggest that discretion be employed with regard to the prescription of commonly available orthotic insoles like arch support cushions.

Topics: Adult; Biomechanical Phenomena; Female; Foot; Gait; Humans; Male; Orthotic Devices; Osteoarthritis, Knee; Running; Shoes; Torque; Treatment Outcome; Walking

The aim of this study was to compare muscle activation patterns and patellofemoral joint morphologies between patients with knee osteoarthritis with and without patellar malalignment.. The subjects were divided into 3 groups. Group A comprised 11 patients with symptomatic knee osteoarthritis without patellar malalignment. Group B comprised 14 patients with symptomatic knee osteoarthritis with patellar malalignment. Group C comprised 10 age-matched subjects with non-knee osteoarthritis as controls.. Isokinetic dynamometry with surface electromyography was used to measure maximal muscle activity in terms of vastus medialis oblique/vastus lateralis ratios. Merchant's view was taken to analyse the bony anatomy of the patellofemoral joint. Recordings were made at angular velocities of 80, 120 and 240 masculine/sec.. The electromyographic ratios of group B were lower than groups A and C for all testing velocities (p<0.05). Group B also had larger sulcus angles, lateral patellar tilt and displacement. The electromyographic ratios correlated negatively with sulcus angles.. Subjects with knee osteoarthritis with patellar malalignment exhibited an imbalance in quadriceps contraction, as confirmed by altered vastus medialis oblique/vastus lateralis ratios associated with larger sulcus angles of the patellofemoral joints. The sulcus angle may be an important contributing factor in causing abnormal patellar tracking in knee osteoarthritis.

Topics: Adult; Aged; Bone Malalignment; Electromyography; Female; Humans; Male; Middle Aged; Muscle Contraction; Muscle, Skeletal; Osteoarthritis, Knee; Patella; Quadriceps Muscle; Radiography; Torque

Osteoarthritis (OA) is a chronic disorder resulting in degenerative changes to the knee joint. Three-dimensional gait analysis provides a unique method of measuring knee dynamics during activities of daily living such as walking. The purpose of this study was to identify biomechanical features characterizing the gait of patients with mild-to-moderate knee OA and to determine if the biomechanical differences become more pronounced as the locomotor system is stressed by walking faster. Principal component analysis was used to compare the gait patterns of a moderate knee OA group (n=41) and a control group (n=43). The subjects walked at their self-selected speed as well as at 150% of that speed. The two subject groups did not differ in knee joint angles, stride length, and stride time or walking speed. Differences in the magnitude and shape of the knee joint moment waveforms were found between the two groups. The OA group had larger adduction moment magnitudes during stance and this higher magnitude was sustained for a longer portion of the gait cycle. The OA group also had a reduced flexion moment and a reduced external rotation moment during early stance. Increasing speed was associated with an increase in the magnitude of all joint moments. The fast walks did not, however, increase or bring out any biomechanical differences between the OA and control groups that did not exist at the self-selected walks.

Topics: Biomechanical Phenomena; Computer Simulation; Female; Gait; Gait Disorders, Neurologic; Humans; Knee Joint; Male; Middle Aged; Models, Biological; Osteoarthritis, Knee; Physical Exertion; Range of Motion, Articular; Torque; Volition; Walking

The purpose of the present study was to investigate the short-term effects of muscle strengthening exercises on the muscle strength in patients with osteoarthritis (OA) of the knee, and to determine whether the beneficial effects of the exercises on the muscles strength, if any, would be maintained over the long-term. Twenty-six patients (mean: 62.8 years) with mild-to-moderate OA of the knee were instructed to perform the exercises, which consisted of once-weekly facility-based strengthening exercises of the knee extensor and flexor muscles with a Medx knee machine at the intensity of 50% of the maximum peak torque (MPT) measured at the baseline (20 timesx3 sets per week), together with daily home-based isometric strengthening exercises (setting and straight leg raising) of the extensor and flexor muscles of the knee (30 times per day). The beneficial effects of the exercises on the MPT values of both the extensor and flexor muscles of the knee that began to be observed from 3 to 6 months after the start of the exercise regimen, regardless of the gender, age, body mass index, or baseline MPT values of the muscles, were maintained for up to 1-3 years, but tended to be no longer observed at 5 years. The present study showed the short-term efficacy of combined facility- and home-based muscle strengthening exercises for the muscle strength in patients with mild-to-moderate OA of the knee, as well as the loss of the beneficial effect of the exercise regimen on the muscle strength over the long-term.

Topics: Age Factors; Aged; Aged, 80 and over; Exercise Therapy; Female; Follow-Up Studies; Humans; Isometric Contraction; Male; Middle Aged; Muscle Strength; Osteoarthritis, Knee; Torque; Treatment Outcome

The purpose of this study was to document torque characteristics and strength recovery of the knee extensors and flexors before and up to 1 yr after unilateral total knee arthroplasty. Our goal was to also document the responsiveness of isokinetic testing over repeated measures.. Thirteen individuals voluntarily participated in this study. Torque production of the knee extensors and flexors was assessed isokinetically at 1.047 and 3.142 radians/sec.. Regardless of time, the knee extensors and flexors on the involved side generated a range of 76 and 82% of the average peak torque produced by the uninvolved side at both 1.047 and 3.142 radians/sec, respectively. At 30 days after surgery, there was a "dip" in both knee extensor and flexor torque production. Responsiveness indices for the knee extensors and flexors ranged from 0.95 to 2.12 at 1.047 radians/sec. At 3.142 radians/sec, the responsiveness indices for the knee extensors and flexors ranged from 0.65 to 2.87.. One year after surgery, there continues to be knee extensor and flexor strength asymmetry between limbs. Moreover, within the first month after surgery, the knee extensors and flexors are at the weakest point compared with before, 60 days, and 1 yr after surgery. Isokinetic testing is a useful tool to document torque production before and in the early time after unilateral total knee arthroplasty.

Topics: Aged; Arthroplasty, Replacement, Knee; Female; Follow-Up Studies; Humans; Knee Joint; Male; Muscle, Skeletal; Osteoarthritis, Knee; Postoperative Period; Preoperative Care; Range of Motion, Articular; Recovery of Function; Torque

Although gait characteristics have been well documented in people with knee osteoarthritis, little is known about the relationships between gait characteristics and performance or disability. Our purpose was to examine the role of knee kinematics and kinetics on walking performance and disability in people with knee osteoarthritis. We also examined whether pain mediated the relationship between the knee adduction moment and performance or disability.. Three-dimensional gait analysis was conducted on 54 people with medial compartment knee osteoarthritis. Performance was quantified with the Six Minute Walk test and disability was self-reported on the Short Form-36. The pain subscale of the Western Ontario McMaster Universities Osteoarthritis Index and the functional self-efficacy subscale of the Arthritis Self-Efficacy scale were completed.. A step-wise linear regression demonstrated that the variance in Six Minute Walk test scores was explained by functional self-efficacy (50%) and the range of knee motion (8%). The variance in Short Form-36 was explained by pain (36%), the peak extension angle (19%) and the range of knee motion (4%). Pain was unrelated to the knee adduction moment so analyses of pain as a mediator of the adduction moment on either performance or disability were halted.. Kinematic output from the motor control system is useful in understanding some variance in current performance and disability in people with knee osteoarthritis. The knee adduction moment was unrelated to these variables and pain did not mediate between the knee adduction moment and performance or disability. Therefore this moment does not explain current clinical status in people with knee osteoarthritis based on the measures of performance and disability used in this study.

Topics: Aged; Arthralgia; Biomechanical Phenomena; Compartment Syndromes; Disability Evaluation; Female; Gait; Humans; Kinetics; Knee Joint; Male; Middle Aged; Motor Skills; Osteoarthritis, Knee; Range of Motion, Articular; Task Performance and Analysis; Torque

The purpose of this study was to document the early history of knee extensor torque production before and after total knee arthroplasty (TKA), explore the relationship between strength assessments, and describe an 8-week resistive-training protocol. Thirty-eight individuals (19 men, 19 women) with unilateral TKA volunteered to participate in this repeated-measures study. For this group, the mean age was 72.23 +/- 5.34 years; height was 168.00 +/- 8.57 cm; and weight was 79.42 +/- 14.57 kg. Torque production of the knee extensors was assessed isokinetically at 60 and 180 degrees .s(-1) before surgery, 30 days after unilateral TKA (+30), and 60 days after unilateral TKA (+60). Torque production was significantly different between limbs at both 60 and 180 degrees .s(-1) (p < 0.0125) before surgery. Torque production was lower at +30 compared with before surgery at both 60 and 180 degrees .s(-1) (p < 0.002). By +60, torque production was greater than at +30 at both 60 and 180 degrees .s(-1) (p < 0.002).

Topics: Aged; Arthroplasty, Replacement, Knee; Female; Humans; Knee Joint; Male; Muscle, Skeletal; Osteoarthritis, Knee; Physical Therapy Modalities; Postoperative Period; Range of Motion, Articular; Time Factors; Torque

To determine if quadriceps activation failure (QAF) moderates the relationship between quadriceps strength and physical function in individuals with knee osteoarthritis (OA).. Quadriceps strength and QAF were measured in 105 subjects (80 females) with radiographically confirmed knee OA using a burst-superimposition maximum voluntary isometric quadriceps torque test procedure. Subjects performed the Get Up and Go test as a physical performance measure of function and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) as a self-report measure of function. A principal component analysis was performed to combine the Get Up and Go score and the WOMAC subscores into a single function score. Hierarchical regression analysis was performed to examine the ability of 3 models to predict physical function (strength = function; strength + QAF = function; strength + QAF + [strength x QAF] = function). Partial F tests were used to compare differences in R(2) values between each model.. Each model independently predicted the principal component score for function. Adding the strength x QAF interaction term with strength to the model resulted in the highest prediction of function. The strength x QAF interaction indicated that subjects with lower levels of quadriceps strength and higher levels of QAF had lower levels of function than those with comparable levels of weakness but low levels of QAF.. The magnitude of QAF serves to moderate the relationship between quadriceps strength and physical function. Physical function may be more severely affected by weakness of the quadriceps muscles in individuals with knee OA who have higher degrees of QAF than those who may have quadriceps weakness, but do not have QAF.

Topics: Exercise Test; Female; Health Status; Humans; Isometric Contraction; Male; Models, Theoretical; Muscle Weakness; Muscle, Skeletal; Osteoarthritis, Knee; Self Care; Severity of Illness Index; Surveys and Questionnaires; Torque

Topics: Adult; Gait; Humans; Knee Joint; Obesity; Osteoarthritis, Knee; Torque; Walking

To determine if men's dress shoes and sneakers increase knee joint torques and play the same role in the development and/or progression of knee osteoarthritis (OA) as women's high-heeled dress shoes.. Three-dimensional data regarding lower extremity torques and motion were collected during walking in 22 healthy men while (1) wearing dress shoes, (2) wearing sneakers, and (3) barefoot. Data were plotted and qualitatively compared; major peak values were statistically compared between conditions.. The external knee varus torque in early stance was slightly greater with the dress shoes and sneakers, but this slight increase can be explained by the faster walking speed with shoes. No significant increases were found in any other of the sagittal, coronal, or transverse knee torques when walking with dress shoes and sneakers compared to barefoot.. Men's dress shoes and sneakers do not significantly affect knee joint torques that may have relevance to the development and/or progression of knee OA.

Topics: Adult; Biomechanical Phenomena; Disease Progression; Humans; Knee Joint; Male; Osteoarthritis, Knee; Risk Reduction Behavior; Shoes; Torque; Walking

To test whether a lateral-wedged insole, inclined at 5 degrees or 10 degrees, significantly reduces knee varus torque during walking in patients with knee osteoarthritis compared with both using no insole and with wearing nonwedged control insoles of the same material and average thickness.. Patients with medial knee osteoarthritis were studied while they walked wearing their comfortable shoes (1) without an insole; (2) with a 5 degrees lateral wedge compared with a nonwedged, 3.175-mm (1/8-in) even-thickness control insole; and (3) with a 10 degrees lateral wedge compared with a nonwedged 6.35-mm ((1/4)-in) even-thickness control insole.. A gait laboratory with 3-dimensional motion analysis and force platform equipment.. Fifteen patients with clinical and radiographic osteoarthritis of the medial compartment of 1 knee.. Not applicable.. Peak external knee varus torques during the stance period of gait. Data regarding lower-extremity joint torques and motions were collected, and knee joint torques using the different insoles and wedges were compared by analysis of variance.. Although responses varied among individuals, as a group, both the 5 degrees and 10 degrees lateral-wedge insoles significantly reduced the knee varus torque during walking compared with walking with no insole and walking with nonwedged 3.175-mm and 6.35-mm control insoles. Compared with no insole, the 5 degrees wedge reduced the peak knee varus torque values by about 6% and the 10 degrees wedge reduced the peaks by about 8%. Although there were no significant differences in speed of walking between the conditions, the 10 degrees wedge and 6.35-mm control insoles were associated with varying degrees of discomfort.. Both wedge insoles are effective in reducing the varus torque during walking beyond what theoretically could be explained by a reduced walking speed or cushioning effect from the insole. These data imply that wedged insoles are biomechanically effective and should reduce loading of the medial compartment in persons with medial knee osteoarthritis. Although the effect of the 5 degrees wedge was smaller, it may be more comfortable than the 10 degrees wedge to wear inside one's own shoes.

Topics: Aged; Biomechanical Phenomena; Female; Foot; Gait; Humans; Knee Joint; Male; Orthotic Devices; Osteoarthritis, Knee; Shoes; Torque; Treatment Outcome; Walking