vendex and Arthralgia

To investigate the relationship between baseball pitching biomechanics and pain, injury, or surgery, in pitchers of all ages and competition levels.. Systematic review.. This study was registered on Prospero (CRD42019137462). Four online databases (MEDLINE, SPORTDiscus, CINAHL, and Embase) from inception to June 13, 2019 were systematically searched. Risk of bias was assessed through the modified Downs and Black.. 967 titles/abstracts were screened with 11 studies (1376 pitchers) included. Four studies used 3D biomechanical analyses, five studies video analysis, and two studies evaluated EMG activity. Level 1b evidence suggests that injured pitchers had greater elbow valgus torque at late arm cocking (injured: 91.6Nm, non-injured: 74.7Nm, p=0.013) and early trunk rotation was predictive of increased upper extremity surgical risk (Hazard Ratio: 1.69 (95% CI 1.02-2.80)). Level 3b evidence observed pitchers with upper extremity surgical history had greater lateral trunk tilt at release (surgery: 29.3°, controls: 23.4°, p=0.035), and flexor carpi ulnaris EMG activity was decreased (injured: 68% MMT, controls: 103% MMT) in pitchers with elbow injury.. Increased elbow valgus torque and early trunk rotation were injury risk factors, and elbow injured pitchers displayed diminished forearm muscle activity. Due to the low power of many of these studies, and the lack of prospective 3D biomechanical studies, other pitching biomechanical variables cannot be ascertained as injury risk factors. Future studies are needed to prospectively assess pitching injury risk through 3D biomechanical methods.

Topics: Adolescent; Adult; Arthralgia; Baseball; Bias; Biomechanical Phenomena; Child; Elbow Joint; Electromyography; Humans; Risk Factors; Rotation; Torque; Torso; Upper Extremity; Video Recording; Young Adult

The aim of the study was to assess the effectiveness of a hybrid training system with walking that simultaneously applies electrical stimulation to the knee extensors/flexors during walking in obese women with knee pain.. This is a randomized, single-blind (assessor), controlled trial. Twenty-eight obese women with knee pain were randomized to 12 weeks of biweekly walking with either hybrid training system with walking or with transcutaneous electrical nerve stimulation (control). Primary outcomes (maximum isokinetic knee extensor torque and maximum isokinetic knee flexor torque) and secondary outcomes (20-m walk time, chair-stand time, stair-climb time, knee pain, and knee-related quality life) were evaluated. Change-point regression analyses were used to model the interaction for the primary outcomes. Two-sample t tests were used on pre-post change scores in secondary outcomes.. Knee extensor torque increased significantly more in the hybrid training system with walking group than the control group when baseline knee extensor torque was greater than 57.2 Nm (P = 0.0033). When baseline knee flexor torque was at 30 or 50 Nm, there was a trend toward greater increase in the hybrid training system with walking group than the control group (P = 0.0566, P = 0.0737, respectively). There were no significant differences between groups in secondary outcomes.. These results suggest that hybrid training system with walking is effective for improving knee extensor torque in obese women with knee pain. However, the superiority of hybrid training system with walking may vary depending on baseline knee muscle strength.

Topics: Aged; Arthralgia; Female; Humans; Knee Joint; Middle Aged; Muscle Strength; Obesity; Resistance Training; Single-Blind Method; Torque; Transcutaneous Electric Nerve Stimulation; Treatment Outcome; Walking

To examine the effect of experimental knee pain on perceived knee pain and gait patterns and to examine the efficacy of transcutaneous electrical nerve stimulation (TENS) on perceived knee pain and pain-induced knee gait mechanics.. Crossover trial.. Biomechanics laboratory.. Recreationally active, individuals without musculoskeletal pain aged 18 to 35 years (N=30).. Thirty able-bodied individuals were assigned to either a TENS (n=15) or a placebo (n=15) group. All participants completed 3 experimental sessions in a counterbalanced order separated by 2 days: (1) hypertonic saline infusion (5% NaCl); (2) isotonic saline infusion (0.9% NaCl); and (3) control. Each group received sensory electrical stimulation or placebo treatment for 20 minutes, respectively.. Perceived pain was collected every 2 minutes using a 10-cm visual analog scale (VAS) for 50 minutes and analyzed using a mixed model analysis of covariance with repeated measures. Gait analyses were performed at baseline, infusion, and treatment. Sagittal and frontal knee angles and internal net joint torque across the entire stance were analyzed using a functional data analysis approach.. Hypertonic saline infusion increased perceived pain (4/10cm on a VAS; P<.05) and altered right knee angle (more flexion and less abduction; P<.05) and internal net joint torque (less extension and greater abduction; P<.05) across various stance phases. TENS treatment reduced perceived pain and improved right sagittal gait abnormalities as compared with placebo treatment (P<.05).. This pain model increases perceived pain and induces compensatory gait patterns in a way that indicates potential quadriceps weakness. However, TENS treatment effectively reduces perceived pain and restores pain-induced gait abnormalities in sagittal knee mechanics.

Topics: Adult; Afferent Pathways; Arthralgia; Biomechanical Phenomena; Cross-Over Studies; Female; Gait; Humans; Knee Joint; Male; Pain Measurement; Pain Perception; Saline Solution, Hypertonic; Torque; Transcutaneous Electric Nerve Stimulation; Young Adult

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals.. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second).. The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences.. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology.

Topics: Adult; Arthralgia; Biomechanical Phenomena; Denmark; Female; Humans; Injections, Intra-Articular; Knee Joint; Male; Muscle Strength; Pain Measurement; Quadriceps Muscle; Resistance Training; Saline Solution, Hypertonic; Time Factors; Torque; Treatment Outcome; Young Adult

Weight-bearing (WB) and non-weight-bearing (NWB) exercises are commonly used in rehabilitation programs for patients with anterior knee pain (AKP).. To determine the immediate effects of isolated WB or NWB knee-extension exercises on quadriceps torque output and activation in individuals with AKP.. A single-blind randomized controlled trial.. Laboratory.. 30 subjects with self-reported AKP.. Subjects performed a maximal voluntary isometric contraction (MVIC) of the quadriceps (knee at 90°). Maximal voluntary quadriceps activation was quantified using the central activation ratio (CAR): CAR = MVIC/(MVIC + superimposed burst torque). After baseline testing, subjects were randomized to 1 of 3 intervention groups: WB knee extension, NWB knee extension, or control. WB knee-extension exercise was performed as a sling-based exercise, and NWB knee-extension exercise was performed on the Biodex dynamometer. Exercises were performed in 3 sets of 5 repetitions at approximately 55% MVIC. Measurements were obtained at 4 times: baseline and immediately and 15 and 30 min postexercise.. Quadriceps torque output (MVIC: N·m/Kg) and quadriceps activation (CAR).. No significant differences in the maximal voluntary quadriceps torque output (F2,27 = 0.592, P = .56) or activation (F2,27 = 0.069, P = .93) were observed among the 3 treatment groups.. WB and NWB knee-extension exercises did not acutely change quadriceps torque output or activation. It may be necessary to perform exercises over a number of sessions and incorporate other disinhibitory interventions (eg, cryotherapy) to observe acute changes in quadriceps torque and activation.

Topics: Adolescent; Adult; Arthralgia; Exercise Therapy; Female; Humans; Isometric Contraction; Knee Joint; Male; Quadriceps Muscle; Resistance Training; Single-Blind Method; Torque; Weight-Bearing; Young Adult

ACL reconstruction with bone patellar tendon bone (BPTB) grafts has been shown to produce dependable results. Recently, reconstructions with double-looped semitendinosus gracilis (DLSG) grafts have become common. The prevailing opinion is that ACL reconstruction with patellar tendon graft produces a more stable knee with more anterior knee pain than DLSG grafts, while the functional results and knee scores are similar. The present study evaluates BPTB grafts fixed with metallic interference screws and DLSG grafts fixed with Bone Mulch Screw on the femur and WasherLoc fixation on the tibia. All else being the same, there is no difference in the outcome between the two grafts and fixation methods. This is a prospective randomized multicenter study. A total of 115 patients with isolated ACL ruptures were randomized to either reconstruction with BPTB grafts fixed with metal interference screws (58 patients) or DLSG grafts (57 patients) fixed with Bone Mulch Screws and WasherLoc Screws. Follow-up was at one and two years; the latter by an independent observer. At two years, one ACL revision had been performed in each group. Eight patients in the DLSG group and one in the BPTB group underwent meniscus surgery in the follow-up period (P = 0.014). Mean Lysholm score at the two year follow-up was 91 (SD +/- 10.3) in the DLSG group and also 91 (SD +/- 10.2) in the BPTB group. Mean KT-1000 at two years was 1.5 mm in the BPTB group and 1.8 mm in the DLSG group (n.s.). At two years, four patients in the BPTB group and three in the DLSG group had a Lachman test grade 2 or 3 (n.s.). More patients in the BPTB group had pain at the lower pole of the patella (P = 0.04). Peak flexion torque and total flexion work were lower in the DLSG group at one year (P = 0.003 and P = 0.000) and total flexion work also at two years (P = 0.05). BPTB ACL reconstruction fixed with interference screws and DLSG fixed with Bone Mulch Screws on the femur and WasherLoc Screws on the tibia produce satisfactory and nearly identical outcomes. Among our patients in the DLSG group, flexion strength was lower, and more patients underwent meniscus surgery in the follow-up period. The BPTB group has more anterior knee pain.

Topics: Adolescent; Adult; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Arthralgia; Bone Screws; Bone-Patellar Tendon-Bone Grafting; Female; Femur; Humans; Male; Menisci, Tibial; Middle Aged; Muscle Strength; Prospective Studies; Range of Motion, Articular; Tendons; Tibia; Torque; Transplantation, Autologous

. 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

To compare a commercially available electric muscle stimulation regimen with a novel form of stimulation for the rehabilitation of the quadriceps muscle, in patients with patellofemoral pain syndrome.. Double-blinded randomized trial with a parallel control group and stratified randomization.. Home-based rehabilitation program assessed in research center.. Eighty patients (47 women, 33 men) with patellofemoral pain syndrome.. One group (EMPI) received 1 uniform constant frequency component of 35Hz. The other (EXPER) group received an experimental form of stimulation that contained 5 simultaneously delivered frequency components of 125, 83, 50, 2.5, and 2Hz. Stimulation was applied to the quadriceps muscles of the affected leg for 1 hour daily for 6 weeks, a total of 42 treatments.. Lower-limb isometric and isokinetic torque, quadriceps fatigue, knee flexion, patellar pain, a step test, quadriceps cross-sectional area, and Kujala patellofemoral score for pain before and after treatment.. Seventy-four patients (43 women, 31 men) completed the trial. Patients in both groups showed significant improvements in all outcomes (P<.05). No significant differences existed between the 2 stimulators in any outcome (P>.05) except for quadriceps cross-sectional area (P=.023).. One form of stimulation was just as efficacious as the other in improving subjective and objective measures.

Topics: Adult; Arthralgia; Double-Blind Method; Electric Stimulation Therapy; Female; Humans; Knee Joint; Male; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Outcome Assessment, Health Care; Torque; Ultrasonography

The goal of this prospective study was to determine the outcome-predictive role of various parameters in the nonoperative treatment of chronic anterior knee pain patients. Thirty patients followed a five-week treatment program, which consisted out of only closed kinetic chain exercises. Prior to this treatment all subjects were evaluated on muscular characteristics, subjective symptoms, weight, sex, duration of symptoms and functional performance. A multiple stepwise regression analysis revealed that the reflex response time of m. vastus medialis obliquus (VMO) (P=0.041; 0.026), and the duration of symptoms (P=0.019; 0.045) were the only two parameters which were significantly associated with the outcome (evaluated by the Kujala score) at five weeks, and at three months. The shorter the duration of symptoms, or the faster the reflex response time of VMO prior to the treatment, the better the outcome after a closed kinetic chain exercise program. The statistical significance of these parameters in this study may be seen as an indication of the importance of these variables as predictors of the outcome of a closed kinetic chain strengthening program. Using this information, it seems clinically important to begin the treatment program before the anterior knee pain becomes more chronic and treatment results become less good.

Topics: Adolescent; Adult; Arthralgia; Athletic Injuries; Exercise Therapy; Female; Humans; Knee Injuries; Male; Muscle Contraction; Muscle, Skeletal; Program Evaluation; Prospective Studies; Reflex, Stretch; Torque; Treatment Outcome

Case study.. To compare knee kinematics and moments of nongiving way trials to a giving way trial during a combined stepping and crossover cutting activity.. The knee kinematics and moments associated with giving way episodes suggest motor control strategies that lead to instability and recovery of stability during movement.. A 27-year-old woman with anterior cruciate ligament deficiency reported giving way while performing a combined stepping and crossover cutting activity. A motion analysis system recorded motion of the pelvis, femur, tibia, and foot using 3 infrared emitting diodes placed on each segment at 60 Hz. Force plate recordings at 300 Hz were combined with limb inertial properties and position data to estimate net knee joint moments. The stance time, foot progression angle, and cutting angle were also included to evaluate performance between trials.. Knee internal rotation during the giving way trial increased 3.2 degrees at 54% of stance relative to the nongiving way trials. Knee flexion during the giving way trial increased to 33.1 degrees at 66% of stance, and the knee moment switched from a nominal flexor moment to a knee extensor moment at 64% of stance. The knee abductor moment and external rotation moment during the giving way trial deviated in early stance.. The observed response to the giving way event suggests that increasing knee flexion may enhance knee stability for this subject. The transverse and frontal plane moments appear important in contributing to the giving way event. Further research that assists clinicians in understanding how interventions can impact control of movements in these planes is necessary.

Topics: Adaptation, Physiological; Adult; Anterior Cruciate Ligament Injuries; Arthralgia; Basketball; Biomechanical Phenomena; Electromyography; Female; Foot; Gait; Humans; Joint Instability; Knee Injuries; Knee Joint; Movement; Muscle, Skeletal; Reproducibility of Results; Rotation; Rupture; Task Performance and Analysis; Torque

Test re-test reliability design.. To determine a reproducible protocol for lower limb simultaneous multi-joint assessments on a healthy group of subjects and a patient group with patellofemoral pain syndrome.. Although single joint assessment with isokinetic dynamometers has been utilised for many years in knee rehabilitation, simultaneous multi-joint assessment has not attracted comparable attention.. Twenty healthy volunteers mean age 30.6 years and 16 patients with patellofemoral pain syndrome mean age 29.6 years performed isometric maximum voluntary contractions and concentric isokinetic contractions of the lower limb. Data were collected on three separate days for resultant extension/flexion peak torque, average power and total work which were analysed using intraclass correlation coefficients with a 95% level of confidence.. In healthy subjects, intraclass correlation coefficients estimates were > or =0.75 for isokinetic peak torque and >0.83 for average power and total work. The intraclass correlation coefficients estimate for isometric peak torque extension was 0.82. In the patient group, intraclass correlation coefficients estimates were >0.82 for isokinetic peak torque and > or =0.75 for average power and total work. The intraclass correlation coefficients estimate for isometric peak torque extension was 0.89. Discarding the first session's data for both groups improved the intraclass correlation coefficients estimates for virtually all assessments.. This study has demonstrated high reproducibility of lower limb multi-joint testing for peak torque, average power, and total work on healthy subjects and then has employed the protocol to demonstrate similarly high reliability on a patient group. It has also highlighted the need for a practice session before the data can be said to be reliable.. Reliability studies often use healthy subject groups, which although useful, have limited relevance to patient populations. This study has not only gained comprehensive reproducibility data on multi-joint assessment in healthy subjects, it has also shown that multi-joint testing can be used safely and reliably in patients with patellofemoral pain syndrome. Clinicians may now be able to measure objectively lower limb function in this patient group both pre and post treatment.

Topics: Adult; Arthralgia; Exercise; Female; Hip Joint; Humans; Knee Joint; Leg Injuries; Male; Muscle Contraction; Reproducibility of Results; Statistics, Nonparametric; 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

Knee joint pain (KJP) is a cardinal symptom in knee pathologies, and quadriceps inhibition is commonly observed among KJP patients. Previously, KJP independently reduced quadriceps strength and activation. However, it remains unknown how disinhibitory transcutaneous electrical nerve stimulation (TENS) will affect inhibited quadriceps motor function. This study aimed at examining changes in quadriceps maximum voluntary contraction (MVC) and central activation ratio (CAR) before and after sensory TENS following experimental knee pain. Thirty healthy participants were assigned to either the TENS or placebo groups. All participants underwent three separate data collection sessions consisting of two saline infusions and one no infusion control in a crossover design. TENS or placebo treatment was administered to each group for 20 min. Quadriceps MVC and CAR were measured at baseline, infusion, treatment, and post-treatment. Perceived knee pain intensity was measured on a 100-mm visual analogue scale. Post-hoc analysis revealed that hypertonic saline infusion significantly reduced the quadriceps MVC and CAR compared with control sessions (P < 0.05). Sensory TENS, however, significantly restored inhibited quadriceps motor function compared with placebo treatment (P < 0.05). There was a negative correlation between changes in MVC and knee pain (r = 0.33, P < 0.001), and CAR and knee pain (r = 0.62, P < 0.001), respectively.

Topics: Adult; Arthralgia; Cross-Over Studies; Female; Humans; Male; Muscle Contraction; Pain Measurement; Quadriceps Muscle; Saline Solution, Hypertonic; Torque; Transcutaneous Electric Nerve Stimulation; Young Adult

Generalized Joint Hypermobility (GJH) is associated with increased risk of musculoskeletal joint pain. We investigated neuromuscular performance and muscle activation strategy.. Girls with GJH and non-GJH (NGJH) performed isometric knee flexions (90°,110°,130°), and extensions (90°) at 20 % Maximum Voluntary Contraction, and explosive isometric knee flexions while sitting. EMG was recorded from knee flexor and extensor muscles.. Early rate of torque development was 53 % faster for GJH. Reduced hamstring muscle activation in girls with GJH was found while knee extensor and calf muscle activation did not differ between groups. Flexion-extension and medial-lateral co-activation ratio during flexions were higher for girls with GJH than NGJH girls.. Girls with GJH had higher capacity to rapidly generate force than NGJH girls which may reflect motor adaptation to compensate for hypermobility. Higher medial muscle activation indicated higher levels of medial knee joint compression in girls with GJH. Increased flexion-extension co-activation ratios in GJH were explained by decreased agonist drive to the hamstrings.

Topics: Adaptation, Physiological; Adolescent; Arthralgia; Cohort Studies; Electromyography; Female; Humans; Isometric Contraction; Joint Instability; Knee Joint; Muscle, Skeletal; Range of Motion, Articular; 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

Iliotibial band syndrome is the leading cause of lateral knee pain in runners. Despite its high prevalence, little is known about the biomechanics that lead to this syndrome. The purpose of this study was to prospectively compare lower extremity kinematics and kinetics between a group of female runners who develop iliotibial band syndrome compared to healthy controls. It was hypothesized that runners who develop iliotibial band syndrome will exhibit greater peak hip adduction, knee internal rotation, rearfoot eversion and no difference in knee flexion at heel strike. Additionally, the iliotibial band syndrome group were expected to have greater hip abduction, knee external rotation, and rearfoot inversion moments.. A group of healthy female recreational runners underwent an instrumented gait analysis and were then followed for two years. Eighteen runners developed iliotibial band syndrome. Their initial running mechanics were compared to a group of age and mileage matched controls with no history of knee or hip pain. Comparisons of peak hip, knee, rearfoot angles and moments were made during the stance phase of running. Variables of interest were averaged over the five running trials, and then averaged across groups.. The iliotibial band syndrome group exhibited significantly greater hip adduction and knee internal rotation. However, rearfoot eversion and knee flexion were similar between groups. There were no differences in moments between groups.. The development of iliotibial band syndrome appears to be related to increased peak hip adduction and knee internal rotation. These combined motions may increase iliotibial band strain causing it to compress against the lateral femoral condyle. These data suggest that treatment interventions should focus on controlling these secondary plane movements through strengthening, stretching and neuromuscular re-education.

Topics: Adolescent; Adult; Arthralgia; Awards and Prizes; Biomechanical Phenomena; Computer Simulation; Female; Hip Joint; Humans; Knee Injuries; Knee Joint; Ligaments; Middle Aged; Models, Biological; Range of Motion, Articular; Running; Syndrome; 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

In total 23 rat knee joint afferent units with conduction velocities of 1.2-17 m/s were recorded extracellularly during inward and outward joint rotations of defined torque using a newly developed torque-meter. There was not a linear relation between the torque and the obtained angle of the joint. The mechanical thresholds of the units ranged from 10 to 60 mNm. During 10 s of stimulation with 60 mNm they responded with 12-300 action potentials. Two mechanosensitive nerve fibres could not be activated via knee joint rotation at any torque at all. The units could be classified according to their response pattern during stimulation: (1) phasic-tonic response behaviour; (2) constant discharge rate; (3) delayed onset of activity. In conclusion, the novel torque-meter allows a precise characterisation of the mechanical threshold and the corresponding response of fine afferent joint units during knee joint rotation.

Topics: Animals; Arthralgia; Electrophysiology; Knee Joint; Male; Mechanoreceptors; Nerve Fibers; Nerve Fibers, Myelinated; Neurons, Afferent; Nociceptors; Physical Stimulation; Range of Motion, Articular; Rats; Rats, Wistar; Research Design; Rotation; Torque