vendex and Tendinopathy

Athletes such as long-distance runners, sprinters, hockey, and/or football players may have proximal hamstring tendinopathy (PHT). Laser therapy has been shown to be effective in tendinopathies. High power laser therapy (HPLT) is used for the treatment of several musculoskeletal conditions; however, its efficacy on PHT has not been investigated. This study is aimed at examining the effects of HPLT on pain and isokinetic peak torque (IPT) in athletes with PHT. The two-arm comparative pretest-posttest experimental design was used with random allocation of 36 athletes aged 18-35 years into two groups (experimental and conventional group). The experimental group included the application of HPLT for 3 weeks. The conventional group included treatment with a conventional physiotherapy program including ultrasound therapy, moist heat pack, and home exercises for a total of 3 weeks. Pain and IPT of the hamstring muscle were measured before and after the application of the intervention. Pain score decreased, and IPT increased significantly (

Topics: Athletes; Hamstring Muscles; Humans; Laser Therapy; Pain; Tendinopathy; Torque

The aim of this study was to explore the efficacy of 16 weeks of extracorporeal shockwave therapy in athletes with patellar tendinopathy.. Athletes with patellar tendinopathy were matched for age, height and body weight and assigned to the experimental group (N.=26) or control group (N.=25). Subjects in the experimental group received 16 rounds (once per week) of extracorporeal shockwave therapy (2000 single shocks; strength, 1.5 to 3.0 bar; shock frequency, 9 to 12 Hz). Subjects in the control group received physical treatments, such as acupuncture, ultrasonic wave, and microwave therapy.. After 16 weeks, Visual Analog Scale (VAS) Score in the experimental group was reduced by 69.4% (P<0.01) compared with that at 0 weeks. Knee joint 60°/s and 240°/s peak torques were increased by 17.2% (P<0.01) and 7.2% (P<0.05), respectively, and extensor endurance by 17.4% (P<0.05). VAS Score in the control group was reduced by 16.9% (P<0.01) at 16 weeks compared with 0 weeks, and the knee joint 60°/s peak torque was increased by 8.2% (P<0.05). For between-groups comparisons, the VAS Score in the experimental group was reduced by 62.7% (P<0.01); whereas knee joint 60°/s and 240°/s peak torques increased by 8.8% and 5.8%, respectively, and extensor endurance by 12.5% (P<0.05). There were no significant differences between male and female subjects (P>0.05).. Extracorporeal shock wave therapy has a positive effect on patellar tendinopathy in athletes, with no gender differences in therapeutic effect. Extracorporeal shock wave therapy may be used to alleviate pain and improve knee joint extensor strength and endurance.

Topics: Adolescent; Adult; Athletes; Extracorporeal Shockwave Therapy; Female; Humans; Knee Joint; Male; Muscle Strength; Pain Management; Tendinopathy; Torque; Young Adult

Our purpose was to investigate the effect of creatine (Cr) supplementation on regeneration periods in tendon overuse injury rehabilitation of adolescent fin swimmers. The participants of this study were injured adolescent competitive fin swimmers (n = 18). The subjects were randomly assigned the creatine (CR) or placebo (PL) groups with a double-blind research design. The subjects were given Cr supplementation or received the placebo as part of the conservative treatment of the tendinopathy. We measured the segmental lean mass (SLM;kg), the ankle plantar flexion peak torque (PFT;N·m), the pain intensity (NRS;values), prior to immobilization, after immobilization (R2) and after the 2nd (R4) and 4th (R6) weeks of the rehabilitation period of the injured limb. The creatine kinase (CK; U/L) enzyme levels were measured before immobilization, and then every 24 hours for four days. There was a significant decrease in SLM (CR by 5.6% vs. PL by 8.9%; p < 0.03) after two weeks of immobilization in both groups (p < 0.001). After four weeks rehabilitation the SLM significantly increased in both groups (CR by 5.5% vs. PL by 3.8%; p < 0.01). The percent changes in PFT after supplementation in R4 (p < 0.001) and R6 (p < 0.03) were significantly different between groups. There was a significant percent increase measured in the CR group (R4 by 10.4%; p < 0.001; R6 by 16.8%; p < 0.001), whereas significant, but lower growth found in the PL group also took place (R4 by 7.1%; p < 0.001; R6 by 14.7%; p < 0.001) after four weeks of rehabilitation. Significantly faster decrease were found in NRS of CR versus PL group during treatment (p < 0.02). We detected significantly lower CK levels increase at the CR group compared to the PL group. The results of this study indicate that Cr supplementation combined with therapeutic strategy effectively supports the rehabilitation of tendon overuse injury of adolescent fin swimmers.

Topics: Adolescent; Child; Creatine; Creatine Kinase; Cumulative Trauma Disorders; Dietary Supplements; Double-Blind Method; Electric Impedance; Female; Humans; Immobilization; Male; Sports Nutritional Physiological Phenomena; Swimming; Tendinopathy; Tendon Injuries; Tendons; Torque

We have prospectively studied calf muscle strength (isokinetic concentric and eccentric muscle strength at 90 degrees/s and 225 degrees/s of angular velocity in 24 patients (17 males and 7 females, mean age 43.0 years) surgically treated for chronic Achilles tendinosis (at the 2-6 cm level in the tendon). The mean follow-up time was 5 years (range 31-82 months). Surgery was followed by immobilization in a weight-bearing below the knee plaster cast for 2-6 weeks, followed by a stepwise increasing strength training programme. Strength measurements (peak torque) were done preoperatively, and 1 and 5 (mean) years postoperatively. Preoperatively, concentric plantar flexion peak torque at 90 degrees/s and 225 degrees/s and eccentric plantar flexion torque at 90 degrees/s were significantly lower (12.3%, 19.7% and 8.5% respectively) on the injured side compared to the non-injured side. Postoperatively, at the 5-year follow-up, 22 out of 24 patients (92%) were satisfied with the operation and active at their desired level (running, tennis, badminton, walking). There was no significant increase in concentric and eccentric calf muscle strength postoperatively. Concentric plantar flexion peak torque at 90 degrees/s and 225 degrees/s and eccentric plantar flexion peak torque at 90 degrees/s were still significantly lower (7.2%, 8.6% and 8.8% respectively) on the injured side compared to the non-injured side. In conclusion it seems that the calf muscle strength deficit seen on the injured side preoperatively in this group of patients remains despite 92% of the patients being pain-free and active in sports or at recreational level after the operation. However, the percentage side-to-side difference is relatively low, and might not have any clinical relevance.

Topics: Achilles Tendon; Adult; Ankle; Athletic Injuries; Female; Follow-Up Studies; Humans; Isometric Contraction; Leg; Male; Middle Aged; Muscle Contraction; Muscle, Skeletal; Patient Satisfaction; Prospective Studies; Range of Motion, Articular; Recovery of Function; Tendinopathy; Torque; Treatment Outcome

Deficits in muscle performance could be a consequence of a reduced ability of a motor neuron to increase the rate in which it discharges. This study aimed to investigate motor unit (MU) discharge properties of each triceps surae muscle (TS) and TS torque steadiness during submaximal intensities in runners with Achilles tendinopathy (AT).. We recruited runners with (n = 12) and without (n = 13) mid-portion AT. MU discharge rate was analysed for each of the TS muscles, using high-density surface electromyography during 10 and 20% isometric plantar flexor contractions.. MU mean discharge rate was lower in the gastrocnemius lateralis (GL) in AT compared to controls. In AT, GL MU mean discharge rate did not increase as torque increased from 10% peak torque, 8.24 pps (95% CI 7.08 to 9.41) to 20%, 8.52 pps (7.41 to 9.63, p = 0.540); however, in controls, MU discharge rate increased as torque increased from 10%, 8.39 pps (7.25-9.53) to 20%, 10.07 pps (8.89-11.25, p < 0.001). There were no between-group difference in gastrocnemius medialis (GM) or soleus (SOL) MU discharge rates. We found no between-group differences in coefficient of variation of MU discharge rate in any of the TS muscles nor in TS torque steadiness.. Our data demonstrate that runners with AT may have a lower neural drive to GL, failing to increase MU discharge rate to adjust for the increase in torque demand. Further research is needed to understand how interventions focussing on increasing neural drive to GL would affect muscle function in runners with AT.

Topics: Achilles Tendon; Electromyography; Humans; Isometric Contraction; Muscle, Skeletal; Patient Discharge; Pilot Projects; Tendinopathy; Torque

This study aimed to investigate short-interval intracortical inhibition (SICI) and muscle function in the triceps surae of runners with mid-portion Achilles tendinopathy (AT).. Runners with (n = 11) and without (n = 13) AT were recruited. Plantar flexor isometric peak torque and rate of torque development (RTD) were measured using an isokinetic dynamometer. Triceps surae endurance was measured as single-leg heel raise (SLHR) to failure test. SICI was assessed using paired-pulse transcranial magnetic stimulation during a sustained contraction at 10% of plantar flexor isometric peak torque.. Triceps surae SICI was 14.3% (95% CI: -2.1 to 26.4) higher in AT than in the control group (57.9%, 95% CI: 36.2 to 79.6; and 43.6% 95% CI: 16.2 to 71.1, p = 0.032) irrespective of the tested muscle. AT performed 16 (95% CI: 7.9 to 23.3, p < 0.001) fewer SLHR repetitions on the symptomatic side compared with controls, and 14 (95% CI: 5.8 to 22.0, p = 0.004), fewer SLHR repetitions on the non-symptomatic compared with controls. We found no between-groups differences in isometric peak torque (p = 0.971) or RTD (p = 0.815).. Our data suggest greater intracortical inhibition for the triceps surae muscles for the AT group accompanied by reduced SLHR endurance, without deficits in isometric peak torque or RTD. The increased SICI observed in the AT group could be negatively influencing triceps surae endurance; thus, rehabilitation aiming to reduce intracortical inhibition should be considered to improve patient outcomes. Furthermore, SLHR is a useful clinical tool to assess plantar flexor function in AT patients.

Topics: Achilles Tendon; Humans; Leg; Muscle, Skeletal; Tendinopathy; Torque

Insertional Achilles tendinopathy (IAT) is a common and painful musculoskeletal condition. The management of IAT commonly involves strengthening of the plantarflexors, although there is currently a paucity of research investigating plantarflexor neuromuscular performance specific to people with IAT.. To compare plantarflexor neuromuscular performance between men with IAT and controls, and to investigate the relationship between plantarflexor neuromuscular performance and patient reported outcome measures for men with IAT.. Case control.. 34 men with IAT (age 43.7 years [SD 10.02], weight 89.6 kg [16.3]) were matched with 34 healthy men (age 42.8 years [SD 8.9], weight 87.2 kg [9.7]). Participants underwent a plantarflexion maximal voluntary isometric contraction (MVIC) task, and a target force matching task. Neuromuscular variables from these tasks include; MVIC, rate of torque development (RTD), electromechanical delay (EMD), and muscle force steadiness. Participants also completed questionnaires regarding; pain and function, and psychological factors.. The IAT group had reduced MVIC (p < 0.01) and RTD, (p < 0.01) compared to controls, however no significant difference in plantarflexor force steadiness (p = 0.08), or EMD (p = 0.71) was observed. Low strength correlations were detected between the VISA-A and RTD (r = 0.37, p = 0.04), kinesiophobia and EMD (r = 0.45, p = 0.03).. This study established impairments in plantarflexor strength and RTD among people with IAT. Plantarflexor force steadiness and EMD is not altered in IAT, which is in contrast to evidence from mid-portion Achilles tendinopathy. Plantarflexor RTD was the only neuromuscular outcome measure linked to symptom severity, which may indicate it is an important rehabilitation finding.

Topics: Achilles Tendon; Adult; Case-Control Studies; Humans; Isometric Contraction; Male; Tendinopathy; Torque

Kabacinski, J, Murawa, M, Fryzowicz, A, Gorwa, J, and Dworak, LB. Lower extremities strength differences in female volleyball players with stage 1 patellar tendinopathy. J Strength Cond Res 36(8): 2230-2235, 2022-The main purpose of the study was to compare the muscle strength between the involved knee (IK) and uninvolved knee (UK) in 12 female volleyball players with stage 1 chronic patellar tendinopathy. Evaluation included the isometric maximal strength to body mass (MS/BM) of the lower extremities extensors for unilateral and bilateral conditions, concentric isokinetic peak torque to body mass (PT/BM) of the hamstrings and quadriceps at 60°·s -1 and 180°·s -1 , IK to UK extensors maximal strength ratio (SR), IK to UK hamstrings (or quadriceps) peak torque ratio (TR), and hamstrings to quadriceps peak TR (H/Q). The results indicated a significantly lower unilateral and bilateral MS/BM of lower extremities extensors for IK than UK ( p < 0.001). However, there were no significant differences in SR variable between the unilateral condition and bilateral condition ( p = 0.448). Only at the 60°·s -1 velocity, significantly lower quadriceps PT/BM for IK compared with the UK ( p < 0.001) and the control group ( p < 0.001) were observed. Torque ratio related to the quadriceps group was significantly lower at 60°·s -1 than 180°·s -1 ( p = 0.004). Furthermore, significantly higher H/Q for IK compared with UK ( p < 0.001) and control group ( p = 0.008) only at 60°·s -1 was found. These findings show a significant isometric strength asymmetry for both unilateral and bilateral conditions and a significant concentric strength asymmetry at the low velocity. This study suggests strengthening the weaker quadriceps group and balancing the strength between hamstrings and quadriceps within the knee with patellar tendinopathy.

Topics: Female; Humans; Knee; Muscle Strength; Muscle, Skeletal; Quadriceps Muscle; Tendinopathy; Torque; Volleyball

Fatigue of the shoulder rotators may cause reduction of the subacromial space (SAS) and contribute to rotator cuff tendinopathy.. To compare the isokinetic peak torques and fatigue ratios of shoulder external rotators (ER) and internal rotators (IR) between elite softball athletes with and without rotator cuff tendinopathy and to investigate their associations with the SAS.. Cross-sectional study.. University laboratory.. Twenty-five elite softball players and 31 asymptomatic sedentary controls participated in this study.. Isokinetic concentric IR and ER peak torque and fatigue ratio were measured at 60°/s and at 180°/s, respectively; and ultrasound measurement of the SAS was measured during 0° and 60° of shoulder abduction.. Athletes with rotator cuff tendinopathy demonstrated lower peak torque in shoulder concentric ER when compared with their healthy counterparts (37.8 [5.8%] vs 43.6 [8.5%]). No significant difference was found in the fatigue ratios of ER, IR, and ER/IR when compared between elite softball athletes with and without rotator cuff tendinopathy (all P > .24). In asymptomatic athletes, greater IR peak torque (r = .583, P = .03), lower ER/IR strength ratio (r = -.605, P = .02), and greater ER/IR fatigue ratio (r = .575, P = .03) were moderately associated with more reduction of the SAS during 0° and 60° of shoulder abduction.. Decreased strength ratio and fatigue ratio of ER/IR were related to reduction of the SAS.

Topics: Adolescent; Adult; Athletic Injuries; Baseball; Female; Humans; Male; Muscle Fatigue; Rotation; Rotator Cuff Injuries; Shoulder Joint; Tendinopathy; Torque; Ultrasonography; Young Adult

Surgical reinsertion of the distal biceps tendon for acute and chronic tears is a widely accepted procedure, but little is known about surgical treatment of distal biceps tendinopathy.. Twenty patients underwent a surgical procedure for distal biceps tendinopathy after failure of conservative treatment. The surgery was performed through a single incision. The biceps tendon was detached, debrided and reinserted using a ToggleLoc (Zimmer Biomet) device. Clinical and radiologic evaluation was performed after a minimum follow-up of 1 year. Quick-Dash score, Liverpool Elbow Score, Mayo Elbow Performance Index, Broberg and Morrey Score and Short HSS Scoring System were used, and isokinetic testing was performed.. The outcome of these five clinical elbow scores showed no clinically relevant differences between the affected and non-affected side. Isokinetic testing of peak torque in flexion and supination showed equal strength between both sides. These results indicate good functional outcome and recovery of flexion and supination, compared to the non-operated side and the normal population.. This study demonstrates that distal biceps tendon debridement and reinsertion is a safe and valid option for patients with distal biceps tendinopathy after failure of conservative treatment.. Level 3 retrospective cohort study.

Topics: Adult; Debridement; Elbow; Elbow Joint; Female; Humans; Male; Middle Aged; Muscle Strength; Patient Satisfaction; Range of Motion, Articular; Replantation; Retrospective Studies; Supination; Tendinopathy; Torque

The plantaris tendon (PT) has been thought to contribute to symptoms in a proportion of patients with Achilles midportion tendinopathy, with symptoms improving after PT excision.. There is compression and differential movement between the PT and Achilles tendon (AT) during ankle plantarflexion and dorsiflexion.. Descriptive laboratory study.. Eighteen fresh-frozen cadaveric ankles (mean ± SD age: 35 ± 7 years, range = 27-48 years; men, n = 9) were mounted in a customized testing rig, where the tibia was fixed but the forefoot could be moved freely. A Steinmann pin was drilled through the calcaneus, enabling a valgus torque to be applied. The soleus, gastrocnemius, and plantaris muscles were loaded with 63 N with a weighted pulley system. The test area was 40 to 80 mm above the os calcis, corresponding to where the injury is observed clinically. Medially, the AT and PT were exposed, and a calibrated flexible pressure sensor was inserted between the tendons. Pressure readings were recorded with the ankle in full dorsiflexion, full plantarflexion, and plantargrade and repeated in these positions with a 5 N·m torque, simulating increased hindfoot valgus. The pressure sensor was removed and the PT and AT marked with ink at the same level, with the foot held in neutral rotation and plantargrade. Videos and photographs were taken to assess differential motion between the tendons. After testing, specimens were dissected to identify the PT insertion. One-way analysis of variance and paired t tests were performed to make comparisons.. The PT tendons with an insertion separate from the AT demonstrated greater differential motion through range (14 ± 4 mm) when compared with those directly adherent to the AT (2 ± 2 mm) ( P < .001). Mean pressure between the PT and AT rose in terminal plantarflexion for all specimens ( P < .001) and was more pronounced with hindfoot valgus ( P < .001).. The PT inserting directly into the calcaneus resulted in significantly greater differential motion as compared with the AT. Tendon compression was elevated in terminal plantarflexion, suggesting that adapting rehabilitation tendon-loading programs to avoid this position may be beneficial.. The insertion pattern of the PT may be a factor in plantaris-related midportion Achilles tendinopathy. Terminal range plantarflexion and hindfoot valgus both increased AT and PT compression, suggesting that these should be avoided in this patient population.

Topics: Achilles Tendon; Adult; Ankle; Ankle Joint; Female; Foot; Humans; Male; Middle Aged; Muscle, Skeletal; Pressure; Tendinopathy; Torque

This study aimed to compare hip abductor muscle strength between individuals with symptomatic, unilateral gluteal tendinopathy (GT), and asymptomatic controls.. Fifty individuals with GT age between 35 and 70 yr and 50 sex- and age-comparable controls were recruited from the community. Maximal isometric strength (torque normalized to body mass) of the hip abductors was recorded in the supine position using an instrumented manual muscle tester. A two-way mixed ANCOVA, with covariates of self-reported pain during testing and pain limiting maximum effort, was used to compare hip abductor strength of the symptomatic and asymptomatic hip between GT and control individuals. Data were expressed as mean and SD, with the pairwise comparisons expressed as mean differences and 95% confidence intervals.. Individuals with GT demonstrated significantly lower hip abductor torque of both their symptomatic and asymptomatic hip than healthy controls (both P < 0.05), with mean strength deficits of 0.35 N·m·kg (32%) on the symptomatic hip and 0.25 N·m·kg (23%) on the asymptomatic hip. In individuals with GT, the symptomatic hip was significantly weaker than the asymptomatic hip with a mean strength deficit of 0.09 N·m·kg (11%) (P < 0.05).. People with unilateral GT demonstrate significant weakness of the hip abductor muscles bilaterally when compared with healthy controls. Although it is not clear whether hip weakness precedes GT or is a consequence of the condition, the findings provide a basis to consider hip abductor muscle weakness in the treatment plan for management of GT.

Topics: Adult; Aged; Case-Control Studies; Exercise Test; Female; Hip; Humans; Male; Middle Aged; Muscle Strength; Muscle Weakness; Muscle, Skeletal; Tendinopathy; Torque

To compare the hip, knee and ankle torques, as well as knee and ankle flexibility between athletes with patellar tendinopathy and asymptomatic controls.. Cross-sectional study.. Laboratory setting.. Fourteen male volleyball, basketball or handball athletes, divided into 2 groups, patellar tendinopathy group (TG; n = 7) and asymptomatic control group (CG; n = 7).. Hip, knee and ankle isometric torques were measured with a handheld dynamometer. Weight-bearing ankle dorsiflexion, hamstring and quadriceps flexibility were measured with a gravity inclinometer.. The TG had 27% lower hip extensor torque when compared to the CG (P = 0.031), with no group differences in knee and ankle torques (P > 0.05). Also, the TG had smaller weight-bearing ankle dorsiflexion (P = 0.038) and hamstring flexibility (P = 0.006) when compared to the CG. Regarding quadriceps flexibility, no group differences were found (P = 0.828).. Strength and flexibility deficits might contribute to a greater overload on the knee extensor mechanism, possibly contributing to the origin/perpetuation of patellar tendinopathy. Interventions aiming at increasing hip extensors strength as well as ankle and knee flexibility might be important for the rehabilitation of athletes with patellar tendinopathy.

Topics: Adolescent; Adult; Athletic Injuries; Basketball; Biomechanical Phenomena; Cross-Sectional Studies; Humans; Isometric Contraction; Lower Extremity; Male; Muscle Strength; Muscle Strength Dynamometer; Patella; Range of Motion, Articular; Tendinopathy; Torque; Volleyball; Weight-Bearing

The purpose of this technical report is to describe a cost-effective and highly reliable methodology to measure mechanical and material properties of the Achilles tendon. Subjects are positioned on an isokinetic dynamometer time synchronized to a diagnostic ultrasound device. A tendon fascicle distal to the soleus is visualized during a ramped isometric maximal plantarflexion contraction. Excursion of the fascicle and tendon torque output yield a force-elongation curve in which mechanical characteristics and material properties are derived. Excellent intrasession and intersession reliabilities were observed for both the dynamometer (intraclass correlation coefficient [ICC] 0.99, 0.95) and excursion (ICC 0.99, 0.93) measures. Practical applications for this methodology include examination of training regimes for optimal tendon adaptation and rehabilitation in the presence of tendinopathy.

Topics: Achilles Tendon; Adult; Female; Humans; Isometric Contraction; Male; Muscle Strength Dynamometer; Tendinopathy; Torque; Ultrasonography; Young Adult

The aim was to compare viscoelastic properties of Achilles tendons between legs in elite athletes with unilateral tendinosis, and to investigate relationships between the properties and explosive performance and clinical severity. Seventeen male athletes (mean ± standard deviation age, 27.3 ± 2.0 years) who had unilateral, chronic middle-portion tendinopathy of the Achilles tendon were assessed by the Victorian Institute of Sport Assessment questionnaire, measurements of tendon viscoelastic properties, voluntary electromechanical delay (EMD), normalized rate of force development (RFD), and one-leg hopping distance. Compared with the non-injured leg, the tendinopathic leg showed reduced tendon stiffness (-19.2%. P < 0.001), greater mechanical hysteresis (+21.2%, P = 0.004), lower elastic energy storage and release (-14.2%, P = 0.002 and -19.1%, P < 0.001), lower normalized RFD at one-fourth (-16.3%, P = 0.02), 2/4 (-17.3%, P = 0.006), and three-fourths maximal voluntary contraction (-13.7%, P = 0.02), longer soleus and medial gastrocnemius voluntary EMD (+26.9%, P = 0.009 and +24.0%, P = 0.004), and shorter hopping distances (-34.1%, P < 0.001). Tendon stiffness was correlated with normalized RFD, voluntary EMD in the medial gastrocnemius, and hopping distances (r ranged from -0.35 to 0.64, P < 0.05). Hysteresis was correlated to the soleus voluntary EMD and hopping distances (r = 0.42 and -0.39, P < 0.05). We concluded that altered tendon viscoelastic properties in Achilles tendinosis affect explosive performance in athletes.

Topics: Achilles Tendon; Adult; Biomechanical Phenomena; Cross-Sectional Studies; Elasticity; Electromyography; Exercise Test; Humans; Isometric Contraction; Male; Muscle, Skeletal; Severity of Illness Index; Statistics, Nonparametric; Surveys and Questionnaires; Tendinopathy; Time Factors; Torque

The purpose of this study was to investigate the in vivo material and mechanical properties of the human Achilles tendon in the presence of tendinopathy. Real-time ultrasound imaging and dynamometry were used to assess Achilles tendon stiffness, Young's modulus, stress, strain, and cross-sectional area (CSA) in 12 individuals with Achilles tendinopathy and 12 age- and gender-matched controls. The results of this study suggest that tendinopathy weakens the mechanical and material properties of the tendon. Tendinopathic tendons had greater CSA, lower tendon stiffness, and lower Young's modulus. These alterations in mechanical characteristics may put the Achilles tendon at a higher risk to sustain further injury and prolong the time to recovery. Results from this study may be used to design treatment strategies that specifically target these deficits, leading to faster and permanent recovery from tendinopathy.

Topics: Achilles Tendon; Ankle Joint; Biomechanical Phenomena; Case-Control Studies; Elastic Modulus; Electromyography; Humans; Male; Muscle Contraction; Muscle Strength Dynamometer; Muscle, Skeletal; Range of Motion, Articular; Recovery of Function; Tendinopathy; Torque; Ultrasonography

Topics: Achilles Tendon; Ankle; Humans; Muscle Stretching Exercises; Muscle, Skeletal; Range of Motion, Articular; Tendinopathy; Tendons; Torque

The single-leg squat on a 25 degrees decline board has been described as a clinical assessment tool and as a rehabilitation exercise for patients with patellar tendinopathy. Several assumptions have been made about its working mechanism on patellar load and patellofemoral forces, but these are not substantiated by biomechanical evaluations.. To investigate knee moment and patellofemoral contact force as a function of decline angle in the single-leg squat.. Five subjects performed single-leg eccentric squats at decline angles of 0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees and 25 degrees (with/without a backpack of 10 kg), and 30 degrees on a board that was placed over a forceplate. Kinematic and forceplate data were recorded by the Optotrak system. Joint moments of ankle, knee and hip were calculated by two-dimensional inverse dynamics.. Knee moment increased by 40% at decline angles of 15 degrees and higher, whereas hip and ankle moment decreased. Maximum knee and ankle angles increased with steeper decline. With a 10 kg backpack at 25 degrees decline, the knee moment was 23% higher than unloaded. Both patellar tendon and patellofemoral forces increased with higher decline angles, but beyond 60 degrees, the patellofemoral force rose steeper than the tendon force.. All single-leg squats at decline angles >15 degrees result in 40% increase in maximum patellar tendon force. In knee flexions >60 degrees, patellofemoral forces increase more than patellar tendon forces. Higher tendon load can be achieved by the use of a backpack with extra weight.

Topics: Adult; Biomechanical Phenomena; Exercise Therapy; Female; Humans; Isometric Contraction; Knee Joint; Male; Movement; Muscle Contraction; Muscle, Skeletal; Patellar Ligament; Range of Motion, Articular; Tendinopathy; Torque; Weight-Bearing

This study investigated the clinical features of patellar tendinopathy (PT), with focus on individuals with unilateral and bilateral PT. A cross-sectional study design was employed to compare individuals with unilateral (n = 14) or bilateral (n = 13) PT and those without PT (control, n = 31). Features assessed included thigh strength (normalized peak knee extensor torque) and flexibility (sit-and-reach and active knee extension), calf endurance (heel-rise test), ankle flexibility (dorsiflexion), alignment measures (arch height and leg length difference), and functional measures (hop for distance and 6 m hop test). Groups were matched for age and height; however, unilateral and bilateral PT had greater mass with a higher body mass index (BMI) than control. Also, bilateral PT performed more sport hours per week than both unilateral PT and control. Unilateral PT had less thigh strength than control and bilateral PT, whereas bilateral PT had more thigh flexibility than control and unilateral PT. Both unilateral and bilateral PT had altered alignment measures compared to control. Features that predicted symptoms in PT were lower thigh flexibility and strength, whereas those that predicted function were higher thigh strength and lower ankle flexibility. These findings indicate that unilateral and bilateral PT represent distinct entities, and that thigh strength appears particularly important in PT as it predicted both symptoms and function in PT.

Topics: Adolescent; Adult; Athletic Injuries; Cross-Sectional Studies; Exercise Test; Female; Humans; Lower Extremity; Male; Muscle Strength; Muscle, Skeletal; Patellar Ligament; Pliability; Reproducibility of Results; Sports Medicine; Tendinopathy; Thigh; Torque

Chronic insertional tendinitis of the Achilles tendon is an overuse injury seen with increasing frequency because of an aging population and an increased interest in sports. We evaluated the change in plantarflexion strength in patients after our surgical technique for chronic insertional Achilles tendinitis.. From our previous clinical series of detachment and reconstruction of the Achilles tendon for the treatment of insertional tendinitis, ten patients were evaluated with an average followup of 32.1 (range 18 to 52) months. The average age was 65.7 years. We developed a mathematical model to predict the difference in plantarflexion strength between a reconstructed ankle and a healthy contralateral one. Isokinetic testing at 60 degrees/second was performed, measuring plantarflexion peak torque, dorsiflexion peak torque, and total work.. Our mathematical model predicted a decrease of 4% in plantarflexion torque after the surgery. Isokinetic testing found no significant differences in plantarflexion torque, dorsiflexion torque, or total work between the operated and nonoperated ankles.. Complete detachment and reconstruction of the Achilles tendon do not decrease the working capacity of the gastrocsoleus muscle.

Topics: Achilles Tendon; Aged; Chronic Disease; Female; Humans; Male; Middle Aged; Models, Theoretical; Muscle, Skeletal; Pliability; Postoperative Period; Tendinopathy; Torque

In an ongoing prospective study of 14 recreational athletes (12 males and 2 females, mean age 44.2 +/- 7.1 years) with unilateral chronic Achilles tendinosis, we investigated the effect of treatment with heavy-loaded eccentric calf-muscle training. Pain during activity (recorded on a VAS scale) and isokinetic concentric and eccentric calf-muscle strength (peak torque at 90 degrees /second and 225 degrees /second) on the injured and noninjured side were evaluated. In this group of patients, we examined areal bone mineral density (BMD) of the calcaneus after 9 months (range 6-14 months) of training. BMD of the injured side (subjected to heavy-loaded eccentric training) was compared with BMD of the noninjured side. Before onset of heavy-loaded eccentric training, all patients had Achilles tendon pain which prohibited running activity, and significantly lower concentric and eccentric plantar flexion peak torque on the injured compared with the noninjured side. The training program consisted of 12 weeks of daily, heavy-loaded, eccentric calf-muscle training; thereafter the training was continued for 2-3 days/week. The clinical results were excellent-all 14 patients were back at their preinjury level with full running activity at the 3 month follow-up. The concentric and eccentric plantar flexion peak torque had increased significantly and did not significantly differ from the noninjured side at the 3 and 9 month follow-up. There were no significant side-to-side differences in BMD of the calcaneus. There was no significant relationship between BMD of the calcaneus and calf-muscle strength. As a comparison group, we used 10 recreational athletes (5 males and 5 females) mean age 40.9 years (range 26-55 years), who were selected for surgical treatment of chronic Achilles tendinosis localized at the 2-6 cm level. Their duration of symptoms and severity of disease were the same as in the experimental group. There were no significant side-to-side differences in BMD of the calcaneus preoperatively, but 12 months postoperatively BMD of the calcaneus was 16.4% lower at the injured side compared with the noninjured side. Heavy-loaded eccentric calf-muscle training resulted in a fast recovery in all patients, equaled the side-to-side differences in muscle strength, and was not associated with side-to-side differences in BMD of the calcaneus. In this group of middle-aged recreational athletes, BMD of the calcaneus was not related to calf-muscle strength.

Topics: Achilles Tendon; Adult; Athletic Injuries; Bone Density; Calcaneus; Chronic Disease; Cumulative Trauma Disorders; Exercise Therapy; Female; Humans; Leg; Male; Middle Aged; Muscle, Skeletal; Prospective Studies; Tendinopathy; Tendon Injuries; Torque; Treatment Outcome; Weight-Bearing

The purpose of this study was to determine whether relationships exist between selected training, anthropometric, isokinetic muscular strength, and endurance, ground reaction force, and rearfoot movement variables in runners afflicted with Achilles tendinitis.. Specifically, we examined differences in selected measures between a noninjured cohort of runners (N = 58) and a cohort of injured runners with Achilles tendinitis (N = 31). Isokinetic, kinetic, and kinematic measures were collected using a Cybex II+ isokinetic dynamometer (Medway, MA), AMTI force plate (500 Hz), and Motion Analysis high-speed videography (200 Hz), respectively. Separate discriminant function analyses were performed on each of the five sets of variables to identify the factors that best discriminate between the injured and control groups.. Years running, training pace, stretching habits (injured runners were less likely to incorporate stretching into their training routine), touchdown angle, plantar flexion peak torque at 180 degrees x s(-1) and arch index were found to be significant discriminators.. A combined discriminant analysis using the above mentioned significant variables revealed that plantar flexion peak torque, touchdown angle, and years running were the strongest discriminators between runners afflicted with Achilles tendinitis and runners who had no history of overuse injury.

Topics: Achilles Tendon; Adult; Anthropometry; Female; Humans; Male; Muscle, Skeletal; Physical Endurance; Risk Assessment; Running; Tendinopathy; Torque; Weight-Bearing