Plantar Flexion Strength Research Articles

Effects of a Targeted Exercise Program on Inter-Leg Asymmetries in Patients with Patellofemoral Pain

Patellofemoral pain (PFP) is often associated with impaired muscle strength, flexibility, and stability. It has been suggested that inter-leg asymmetries have an important role in increasing the risk of musculoskeletal injuries, including PFP. Thus, the aim of this study was to identify significant asymmetries and determine the effects of a symmetry targeted exercise program in patients with PFP. Eighteen patients aged 13 to 54 years (24.17 ± 12.52 years) with PFP participated in this study. Strength, flexibility and stability outcomes of the trunk, hip, knee and ankle muscles were assessed. A single-group pretest–posttest design was used to assess changes in inter-leg and agonist–antagonist asymmetries resulting from the 8-week period of the supervised exercise program. Results indicated a significant improvement in inter-leg symmetry regarding bilateral stance in a semi-squat position (p = 0.020, d = 0.61, df = 17) and ankle plantarflexion (p = 0.003, d = 0.32, df = 17) and ankle dorsiflexion strength (p < 0.001, d = 0.46, df = 17). In addition, the ratio of ankle dorsiflexion/plantarflexion (p = 0.036, d = 1.14, df = 17) and hip extension/flexion (p = 0.031, d = 0.94, df = 16) changed significantly during the intervention period. To our knowledge, this was the first study to evaluate inter-leg asymmetries resulting from a period of a supervised exercise program. The results indicate that an exercise program focusing on individual asymmetries may influence specific deficits and contribute to better rehabilitation outcomes.

Measuring recovery after open lower limb fractures: combined objective functional tests and global perceived recovery outperform narrower metrics and a standard generic patient reported outcome measure

BackgroundOpen lower limb fractures are serious injuries requiring combined ortho-plastic surgery and have significantly worse outcomes than similar closed fractures. There is little objective published data to determine which functional outcome measures best reflect progress or completeness of physical recovery.Our hypothesis was that objective measures combining strength, mobility and balance would better reflect recovery than isolated parameters (e.g. range of motion ROM) and would compare well to patients’ perceived recovery.MethodsAdult open lower limb fracture patients were reviewed 6 and 12 weeks, 6, 9 and 12 months post-injury. The mechanism, injury pattern, age, gender and treatment were recorded. Isolated parameter objective functional outcome measures (OFOMs) (ROM and MRC strength grade) were compared to combined OFOMs (timed up and go, comfortable gait speed and fast gait speed, Edgren Side Step Test (TUAG, CGS, FGS, ESST) and Single Leg balance. Patient reported outcomes were recorded (Global Perceived Effect (GPE) score and Disability Rating Index (DRI)). Statistical analysis used non-parametric tests (e.g. Spearman correlation) compared each with time since injury.ResultsSixty-eight patients (54 male) with a median age of 45(20–75) years. Of the 19 isolated OFOMs, only knee flexion and ankle plantar flexion ROM and strength improved with time (Spearman correlation p = 0.042, 0.008, 0.032, 0.036 respectively). TUAG, ESST, CGS, FGS and GPE scores showed significant improvement (Spearman correlation p < 0.001). Patients’ estimation of recovery paralleled these measures (Spearman correlation p < 0.001) with all but 2 patients achieving the minimum clinical important difference in DRI by 12 months compared to baseline. However, the GPE score had a higher proportion of improving responses than DRI at each time-point.DiscussionFunctional recovery is a key determinant in patients returning to work, providing for themselves and their family or resuming independent living for older patients. This study has demonstrated time-related improvements in combined OFOMs measuring mobility, strength, agility and balance paralleling patients’ perception of recovery in the 12 months after open lower limb fractures. Over the same time-frame, the simple GPE score compared favourably with the DRI. Such parameters could become part of a defined core outcomes set. Focussing rehabilitation towards these combined OFOMs may help hasten recovery.Trial registrationSouth West Wales REC 06/WMW02/10).

All-Inside Anterior Cruciate Ligament Reconstruction Using an Anterior Half of the Peroneus Longus Tendon Autograft.

Background:The peroneus longus tendon (PLT) has been used as a graft in many orthopaedic surgical procedures because of its comparable biomechanical strength with the native anterior cruciate ligament (ACL). Despite its potential, few studies have been performed to investigate the clinical reliability of ACL reconstruction using a PLT autograft.Purpose:To assess the clinical outcomes and donor-site morbidity of ACL reconstruction using an anterior half of the PLT (AHPLT) autograft in patients with an isolated ACL injury.Study Design:Case series; Level of evidence, 4.Methods:Between January 2016 and January 2017, a total of 21 patients with an isolated ACL injury underwent all-inside single-bundle ACL reconstruction using an AHPLT autograft. Knee stability was assessed using the Lachman test, pivot-shift test, and KT-2000 arthrometer (side-to-side difference) with 134-N anterior force and at 30° of knee flexion. Knee function was evaluated using the International Knee Documentation Committee score, Lysholm score, and Tegner score. Donor-site morbidity was assessed using ankle eversion and plantarflexion strength as well as the American Orthopaedic Foot & Ankle Society scoring system and the Foot and Ankle Disability Index.Results:At a mean final follow-up of 40.1 months (range, 36-48 months), the KT-2000 arthrometer side-to-side difference was significantly lower compared with preoperatively (1.1 ± 0.62 vs 7.0 ± 2.18 mm, respectively; P < .001). The mean preoperative International Knee Documentation Committee, Lysholm, and Tegner scores were 52.0 ± 8.27, 50.9 ± 8.50, and 1.8 ± 0.87, respectively, increasing significantly to 94.2 ± 2.61, 95.2 ± 2.64, and 6.8 ± 1.50, respectively, at final follow-up (P < .001 for all). All patients had grade 5 muscle strength in ankle eversion and plantarflexion at the donor site, with mean American Orthopaedic Foot & Ankle Society and Foot and Ankle Disability Index scores of 96.8 and 97.6, respectively. No complications or reoperations occurred.Conclusion:All-inside ACL reconstruction using an AHPLT autograft produced good functional scores and stability without obvious ankle-site morbidity.

Differences in predictors for gait speed and gait endurance in Parkinson's disease.

Both gait speed and gait endurance directly impact independence and community engagement for individuals with Parkinson's disease (PD). However, factors accounting for variability in gait speed and gait endurance performance are unclear. The purpose of this study was to investigate whether key factors associated with gait speed in individuals with PD also predicted gait endurance. Community dwelling ambulatory individuals with PD were recruited for a single session. Key measures included 10 Meter Walk Test (10MWT) and 6 Minute Walk Test (6MWT) and key factors: age, disease severity [Movement Disorders Society United Parkinson's Disease Rating Scale (motor scale only) (MDS-UPDRS motor)], plantar flexor strength [Calf Raise Senior (CRS)], fatigue [Fatigue Severity Scale (FSS)], cognition [Montreal Cognitive Assessment (MoCA)], and balance [Four Square Step Test (FSST)]. Multiple linear regression analyses were conducted to determine clinical relationships. Seventy-two individuals with PD (mean (standard deviation) (age = 70.83 (7.91) years; 50 males; MDS-UPDRS motor = 30.67 (13.50)) completed all assessments. The model predicting gait speed was significant, F(6, 65) = 15.143, p <.001, accounting for 54 % of the variance. Of the predictor variables age, MDS-UPDRS motor, CRS, MoCA and FSST scores were significant predictors. The model predicting gait endurance was significant, F(6, 65) = 15.608, p <.001, accounting for 55 % of the variance. Of the predictor variables, age, MDS-UPDRS motor scale, and CRS scores were significant predictors. Gait speed and gait endurance are similarly influenced by age, motor impairment, and plantarflexion strength. However, cognition and balance were predictors only of gait speed, which may suggest unique task differences exist between gait speed and gait endurance.

Daily 30-min exposure to artificial gravity during 60\xa0days of bed rest does not maintain aerobic exercise capacity but mitigates some deteriorations of muscle function: results from the AGBRESA RCT

PurposeSpaceflight impairs physical capacity. Here we assessed the protective effect of artificial gravity (AG) on aerobic exercise capacity and muscle function during bed rest, a spaceflight analogue.Methods24 participants (33 ± 9 years, 175 ± 9 cm, 74 ± 10 kg, 8 women) were randomly allocated to one of three groups: continuous AG (cAG), intermittent AG (iAG) or control (CTRL). All participants were subjected to 60 days of six-degree head-down tilt bed rest, and subjects of the intervention groups completed 30 min of centrifugation per day: cAG continuously and iAG for 6 × 5 min, with an acceleration of 1g at the center of mass. Physical capacity was assessed before and after bed rest via maximal voluntary contractions, cycling spiroergometry, and countermovement jumps.ResultsAG had no significant effect on aerobic exercise capacity, flexor muscle function and isometric knee extension strength or rate of force development (RFD). However, AG mitigated the effects of bed rest on jumping power (group * time interaction of the rmANOVA p < 0.001; iAG − 25%, cAG − 26%, CTRL − 33%), plantar flexion strength (group * time p = 0.003; iAG − 35%, cAG − 31%, CTRL − 48%) and plantar flexion RFD (group * time p = 0.020; iAG − 28%, cAG − 12%, CTRL − 40%). Women showed more pronounced losses than men in jumping power (p < 0.001) and knee extension strength (p = 0.010).ConclusionThe AG protocols were not suitable to maintain aerobic exercise capacity, probably due to the very low cardiorespiratory demand of this intervention. However, they mitigated some losses in muscle function, potentially due to the low-intensity muscle contractions during centrifugation used to avoid presyncope.

Total ankle arthroplasty: Strength, pain, and motion

BackgroundWhile outcomes such as pain and ankle motion are well researched, information regarding the effect of total ankle arthroplasty on ankle plantarflexion strength is extraordinarily limited. The purpose of this study was to evaluate ankle plantarflexion strength before and after total ankle arthroplasty, and examine the interplay of pain, motion, and strength. MethodsThis prospective case-control study included 19 patients with end-stage ankle arthritis who received a total ankle arthroplasty and 19 healthy control participants matched for age, sex, and body mass index. Pain was measured with a numeric pain rating scale. Passive sagittal plane ankle range of motion (°) and isokinetic ankle plantarflexion torque (Nm/kg) at 60 and 120°/s were measured with an instrumented dynamometer. t-tests or non-parametric tests were used to evaluate outcomes across time and between groups. Bivariate correlations were performed to evaluate the interplay of postoperative pain, motion, and torque. FindingsPatient pain and motion improved between the preoperative and six-month postoperative time points (d ≥ 0.7). Ankle plantarflexion torque was not different across time (d ≤ 0.5), but was lower than control group values postoperatively (d ≥ 1.4). Significant correlations between pain and motion (r = −0.48), but not torque (−0.11 ≤ r ≤ 0.13), were observed. InterpretationUnchanged following surgery, impairments in muscle performance following total ankle arthroplasty do not appear to be changed by improved pain or motion. These findings provide impetus for postoperative strengthening interventions.

A new simpler approach to measure the strength of toe plantar flexion requiring no mechanical restraint with a light-weight device.

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.

Effects of whole-body vibration training on calf muscle function during maximal isometric voluntary contractions.

The purposes of this study were to determine the impact of 6weeks of whole-body vibration training (WBVT) on maximum voluntary plantar flexor strength, muscle activity via surface electromyography (EMG), and muscle architecture measured at rest and during maximal contraction at different ankle joint angles in young healthy adults. Using a single-blind study design, 28 healthy men and women were randomly assigned to control (CG; N=14, 7 women) or whole-body vibration training (WBVG; N=14, 7 women) groups. Vibration training (20-25minutes; standing with knees flexed) was performed 3week-1 for 6weeks (18 sessions). Maximum isometric plantar flexor torque, muscle activity (medial and lateral gastrocnemius EMG) and medial gastrocnemius fascicle angle and length at rest and maximum contraction were tested at four ankle joint angles (ranging 45° to -15°; 0°=anatomical) before and after training. Significant increases (24.7%-37.5%) were observed in peak torque (N∙m∙kg-1 ;%) at -15°, 0°, 15° and 30° joint angles from pre- to post-intervention in WBVG, which were different to CG (no change) and greater at longer muscle lengths. No between-group differences were observed in changes in EMG amplitudes measured during contraction or muscle architecture parameters at rest or during contraction. Six weeks of WBVT in young, healthy adults increased isometric plantarflexion strength at multiple joint angles, without detectible changes in EMG, muscle architecture, or body composition. Therefore, WBVT can significantly improve maximum plantar flexor strength at multiple joint angles (muscle lengths) in young healthy men, although the mechanisms underpinning the changes are currently unclear.

Factors contributing to racial differences in gait mechanics differ by sex

BackgroundRacial differences in gait mechanics have been recently reported, but we don’t know what factors may drive differences in gait and whether these factors are innate or modifiable. The answers to those questions will inform both basic research and clinical interventions and outcomes. Research questionDo anthropometric, strength, and health status measures explain racial differences in gait between African Americans (AA) and white Americans (WA)? MethodsVenous blood samples, anthropometric measures, lower extremity strength, and an assessment of health status were collected from 92 participants (18–30 years old) as part of an Institutional Review Board-approved study. 3D motion capture and force plate data were recorded during 7 walking trials at set regular (1.35 m/s) and fast (1.6 m/s) speeds. Racial differences in gait were identified at both speeds. Correlations between anthropometric, strength, and health status independent variables and outcome measures were computed after stratifying data by sex. Stepwise linear regression models evaluated whether the inclusion of anthropometric, strength, and health status independent variables explained racial effects. ResultsIn males, no racial differences in gait were explained by independent variables. Q-angle and ankle dorsiflexion strength accounted for racial differences in self-selected walking speed in females. Racial differences in ankle plantarflexion angle were explained by ankle plantarflexion strength differences. SignificanceFactors that explain racial differences in gait in females were both innate and modifiable. These data make clear that it is important to include racially diverse normative gait databases in research studies. These results also identify potential intervention targets aimed at reducing racial health disparities.

Midterm functional performance following open surgical repair of acute Achilles tendon rupture

IntroductionVarious impairments such as soleus atrophy and consecutive functional deficits in end-range plantarflexion have been described in surgical repair of acute Achilles tendon rupture. The aim of this study was to assess the functional performance at midterm following open surgical repair.Materials and MethodsThis cross-sectional study includes n = 52 patients which were tested on average 3.5 ± 1.4 years postoperatively using three different functional performance tests and patient-reported outcome measures. Two different surgical techniques (anatomical repair = AR vs. conventional repair = CR) were compared in a subanalysis. The testing included isokinetic strength testing, a novel setup of heel-rise testing using a marker-based 3D motion analysis system and a gait analysis.ResultsAt an average 3.5 years post-surgery, there is a persisting deficit in plantarflexion strength of 10.2%. Moreover, analysis of maximum peak torque angle and strength deficits according to the plantarflexion angle revealed that these deficits are not equally distributed across the range of motion. AR results in a significantly smaller deficit at 10° of plantarflexion compared to CR (13.9 vs. 29.9%, p < 0.05). This reflects into the functional performance during different modalities (static vs. dynamic) in this novel method of heel-rise testing.ConclusionIn summary, there are persisting functional deficits at > 3 years following Achilles tendon repair which range from strength deficits to specific impairments of functional performance e.g. during heel rise. Anatomical reconstruction is associated with an improved functional performance potentially due to a more symmetric strength during end-range plantarflexion which transfers into a higher satisfaction during athletic activities.Level of evidenceIII, retrospective cohort study

Do the heel-rise test and isometric strength improve after Achilles tendon repair using Dresden technique?

BackgroundAchilles’ tendon ruptures result in impaired plantar flexion strength and endurance. It is interesting to know the plantar flexion strength, the number of heel-rise repetitions, and the maximal calf circumference following Achilles’ tendon ruptures repair. MethodsBoth the injured and non-injured legs of thirty male patients with Achilles’ tendon ruptures treated with the percutaneous Dresden technique were compared with the ankle function of 30 healthy participants. Rehabilitation involved partial weight-bearing for three weeks and then increased to full weight-bearing and ankle exercises. ResultsThe injured legs had weaker plantar flexion strength (1.64 ± 0.17 Nm/kg) compared with the non-injured legs (1.91 ± 0.24 Nm/kg; p = 0.002) and the healthy participants’ legs (1.93 ± 0.32 Nm/kg; p < 0.001). The non-injured leg had greater ability in doing heel-rise repetitions (39.4 ± 6.1 rep.) compared with the injured legs (37.2 ± 5.7 rep.; p < 0.023) and the healthy participants’ legs (31.0 ± 13.0 rep.; p < 0.001). ConclusionsThe injured leg had not recovered full isometric strength but had improved heel-rise repetition.

Machine-assisted foot stretching in the elderly: a comparison with self-stretching

[Purpose] Self-stretching is the traditional at-home stretching method of choice. We developed an automatic foot-stretching machine to perform effective dorsiflexion stretching safely and easily at home. The effects of automatic stretching using our machine and self-stretching were investigated and compared. [Participants and Methods] Twelve healthy elderly people participated in the study. Automatic dorsiflexion static stretching was performed with the right foot, and self-stretching using a towel was performed with the left foot. Before and after each stretching, passive range of motion in dorsiflexion, maximal voluntary contraction strength in plantarflexion, passive resistive torque during passive dorsiflexion, and displacement of the muscle-tendon junction of the medial gastrocnemius muscle were measured. [Results] The range of motion in dorsiflexion had a significantly greater increase after automatic stretching than after self-stretching. The maximum strength in plantarflexion tended to decrease after automatic stretching but did not decrease after self-stretching. The passive resistive torque in both types of stretches decreased in some of the participants but increased in others. The displacement of the muscle-tendon junction of the medial gastrocnemius tended to shorten during automatic stretching as compared with self-stretching. [Conclusion] Foot stretching using a machine is as effective as self-stretching and tends to affect the tendon rather than the muscle.

Foot Posture, Muscle Strength, Range of Motion, and Plantar Sensation in Overweight and Obese.

The purpose of the study was to investigate the foot posture, ankle muscle strength, range of motion (ROM), and plantar sensation differences among normal weight, overweight, and obese individuals. One hundred and twenty-three individuals (42 normal weight, 40 overweight, and 41 obese) aged between 18 and 50 years participated in the study. Foot posture, ankle muscle strength, ROM, plantar sensation, and foot-related disabilities were evaluated. The relative muscle strength of left plantar flexors and invertors and light touch sensation of the left heel were significantly lower in obese individuals compared with overweight and normal weight (P < .016) individuals. Obese individuals had significantly reduced relative muscle strength of plantar flexors, dorsiflexor, and invertors, plantar flexion and inversion ROM in the left foot; and light touch sensation of the right heel compared with normal weight (P < .016) individuals. Foot Posture Index scores were significantly higher in obese individuals compared with overweight (P < .016) individuals. There were no significant differences in absolute muscle strength, vibration sensation, and foot-related disability scores among the 3 groups (P > .05). Obesity was found to have adverse effects on ankle muscle strength, ROM, and plantar light touch sensation. Vibration sensation was not affected by body mass index, and foot-related disability was not observed in obese adults.

Relationship between postural sway on an unstable platform and ankle plantar flexor force steadiness in community-dwelling older women

BackgroundForce steadiness is evaluated as force variability during constant force exertion around a target level. Ankle plantar flexor force steadiness is reported to be related to postural sway on an unstable platform in healthy young adults; however, this relationship in older adults is unclear. Research questionThis study aimed to investigate whether ankle plantar flexor force steadiness was related to postural sway on stable and unstable platforms in older adults. MethodsTwenty-six community-dwelling older women participated in this study (72 ± 6 years). Maximal isometric strength and force steadiness at 5%, 20 %, and 50 % of the maximal strength of ankle plantar flexion were assessed. Postural sway in the anteroposterior direction during bipedal standing was measured on stable and unstable platforms. ResultsThe results showed that force steadiness at any intensity level and maximal isometric strength were not related to postural sway on the stable platform. Force steadiness at 20 % of maximal strength alone was significantly correlated with postural sway on the unstable platform (ρ = 0.441, p < 0.05). SignificanceThese results indicate that the ability to control muscle force could be important for postural stability on an unstable platform in older adults.

Effect of toe exercises and toe grip strength on the treatment of primary metatarsalgia

BackgroundThe relationship of metatarsalgia and toe function is poorly understood. We investigated the efficacy of toe exercises for the treatment of metatarsalgia.MethodsForty-one (56 feet) metatarsalgia patients (mean age ± SD: 63.4 ± 10.6) underwent toe strength measurement. We recorded pre- and post-treatment VAS score, AOFAS score, marble pickup, single-leg standing time (SLST), and compared in two subgroups to evaluate impact of disease duration on treatment outcome.ResultsPost treatment, toe plantarflexion strength improved (all p < 0.01); VAS scores decreased (p < 0.01); AOFAS scores, marble pickup, and SLST improved (all p < 0.01). Patients symptomatic for > 1 year had significantly lower changes in VAS scores (p < 0.01). Multivariate analysis showed patients with longer disease duration, and larger body mass index had significantly lower improvement in VAS scores (p = 0.029 and p = 0.036, respectively). Device consistency assessed by ICC was excellent (0.89–0.97).ConclusionToe function and metatarsalgia are improved by toe exercises, suggesting that they are closely related.

Relationship between lower limb muscle strength and hallux valgus severity in older people

ObjectiveTo examine differences in lower limb muscle strength between older people with varying degrees of hallux valgus deformity. MethodsMuscle strength was measured at the knee, ankle and foot using hand-held dynamometry and a clinical test of toe strength (the paper grip test) in 157 older people (99 women and 58 men) aged 65 to 91 (mean 74.1, SD 5.9) years. Hallux valgus severity was documented as none, mild, moderate or severe using validated photographs. Differences in muscle strength according to hallux valgus severity were evaluated using analysis of variance, adjusting for age. Paper grip test performance was compared across the hallux valgus severity groups using the chi-square (χ2) statistic. ResultsKnee extension, ankle joint dorsiflexion, ankle joint plantar flexion, ankle joint inversion, ankle joint eversion and lesser toe plantarflexion strength were not significantly different across the four hallux valgus severity groups. However, there was a significant, dose-response reduction in hallux plantarflexion strength with increasing severity of hallux valgus. This persisted after adjustment for age (F3 = 5.5, p = 0.001) with a medium effect size (partial η2 = 0.10). The number of participants who could successfully complete the paper grip test of the hallux significantly reduced across the four hallux valgus categories (χ2 = 18.5, p < 0.001). ConclusionsThere is a specific and progressive reduction in hallux plantarflexion strength with increasing severity of hallux valgus in older people. This finding has potential implications for both the aetiology and treatment of this common and disabling condition.

Endoscopic reconstruction for chronic Achilles tendon ruptures using a hamstring tendon autograft

BackgroundTo determine the safety and efficacy of endoscopic reconstruction of chronic Achilles tendon ruptures using a hamstring tendon autograft at mid-term follow-up. MethodsWe reviewed the medical records of patients with chronic Achilles tendon rupture treated surgically by endoscopic reconstruction using a hamstring tendon autograft at our institution between March 2010 and October 2015. Radiologic outcomes were assessed using pre- and postoperative magnetic resonance imaging (MRI). Functional outcomes were evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle–Hindfoot Scale, the Plantar Flexion Strength (PFS), the Victorian Institute of Sport Assessment-Achilles (VISA-A) scale, the Visual Analogue Scale (VAS) pain score, and the Arner-Lindholm standard. All patients achieved primary healing with no lengthening of the Achilles tendon, skin necrosis, infection, deep vein thrombosis or other complications. ResultsMean follow-up period was 15 ± 3 months (range, 12–18 months). There was no Achilles tendon re-rupture. MRI examination revealed that Achilles tendon continuity was restored. Patients’ mean AOFAS, PFS, and VISA-A scores were significantly higher and mean VAS pain score was significantly lower after surgery compared to before (P < 0.05). According to Arner-Lindholm standards, there were twenty (76.9%) excellent, six (23.1%) good, and zero bad outcomes. ConclusionEndoscopic reconstruction utilizing a hamstring tendon autograft is a safe and efficacious option for repair of chronic Achilles tendon ruptures. Studies with larger sample sizes and a longer follow-up are required to confirm the advantage of this technique compared to open surgery.

Contribution of Achilles tendon mechanical properties to torque steadiness in persons with transfemoral amputation.

How Achilles tendon mechanics and plantar flexion strength and torque steadiness are altered in the intact leg of persons with trauma-related amputation is unknown. Understanding Achilles tendon mechanics following amputation will further inform rehabilitation approaches to enhance posture, balance, and force control. Conduct a pilot study to quantify plantar flexion maximal voluntary contraction torque, torque steadiness, and Achilles tendon mechanics in persons with unilateral trauma-related transfemoral amputation and controls without amputation. Cross-sectional study. Isometric plantar flexion maximal voluntary contractions were performed with the intact leg of ten males with transfemoral amputation (48 ± 14 years) and the dominant leg of age-matched male controls without amputation. Torque steadiness was calculated as the coefficient of variation in torque over 6 s during submaximal tracking tasks (5%, 10%, 25%, 50%, and 75% maximal voluntary contraction). Achilles tendon elongation and cross-sectional area were recorded with ultrasound to calculate strain, stress, and stiffness. Maximal voluntary contraction and torque steadiness did not differ between persons with amputation (90.6 ± 31.6 N m, 3.7 ± 2.0%) and controls (95.8 ± 26.8 N m, 2.9 ± 1.2%; p > 0.05). Tendon stiffness (21.1 ± 18.2 N/mm) and strain (5.2 ± 1.3%) did not differ between groups (p > 0.05). Tendon cross-sectional area was 10% greater in persons with amputation leading to 29% lower stress (p = 0.021). Maximal voluntary contraction was a predictor of a lower coefficient of variation in torque (R2 = 0.11, p < 0.05). Persons with trauma-related transfemoral amputation do not differ in plantar flexion maximal voluntary contraction and torque steadiness of the intact leg compared with controls without amputation. Larger tendon cross-sectional area reduces stress and enables distribution of force across a greater area.

Age-Related Differences in the Effect of Prolonged Vibration on Maximal and Rapid Force Production and Balance Ability.

We tested the hypothesis that older adults would not likely experience deficits in maximal and explosive plantar flexion strength and standing balance performance induced by prolonged Achilles tendon vibration compared with young adults. Fifteen older men (OM, 73 ± 5 years) and 15 young men (YM, 24 ± 4 years) participated in two interventions on different days: lying in a quiet supine position for 30 min with or without prolonged vibration to the Achilles tendon. Before and after the interventions, maximal voluntary contraction (MVC) torque during plantar flexion, rate of torque development (RTD), and center of pressure (COP) speed during single-leg standing were measured. The root mean square of the electromyogram (RMS-EMG) during performance and V-wave and voluntary activation during MVC were assessed. The MVC torque (7 ± 7%) and RTD (16 ± 15%) of YM but not OM significantly decreased after vibration. In addition, the relative changes observed in YM positively correlated with changes in RMS-EMG of the medial gastrocnemius (MG) (MVC torque and RTD) and in MG V-wave and voluntary activation (MVC torque). COP speed significantly increased (16 ± 20%) in YM only after vibration and was accompanied by increased activation of the lateral gastrocnemius. This is the first study to show that the effects of prolonged Achilles tendon vibration on strength and balance performances were apparent in young adults only. The differences between the age groups may be related to the attenuated gastrocnemius neuromuscular function in older adults.

Increased Strength following Achilles Tendon Rupture Repair is Associated with Return to Same Level of Play in Patients with Higher Pre-Injury Level of Activity

Category:Hindfoot; Sports; TraumaIntroduction/Purpose:Rupture of the Achilles tendon is a common injury that requires a lengthy duration of recovery and rehabilitation. Patients of various levels of physical activity, ranging from professional high-impact sports to low-impact recreational activities, can be affected by this injury. Often, one of the most important outcomes from the patient’s perspective is the ability to return to the same pre-injury level of sporting activity after recovery. The objective of the current study is to examine the relationship between global ankle strength and the ability to return to previous level of play following surgical repair of an Achilles tendon tear.Methods:Patients aged 18-50 years old at a minimum 1-year post-op from surgical repair of an isolated Achilles tendon rupture were recruited to return for a study visit. Patients reported both pre-injury and current activity level using the 10-point Tegner Activity Level Scale. Isokinetic strength testing was performed and the Isokinetic Strength Score (ISS) was calculated using maximal effort dorsiflexion and plantarflexion strength at 30o/s, 90o/s, and 240o/s comparing the operative and uninvolved extremity. The primary outcome was the patients’ ability to return to same level of play or within 1 Tegner activity level. Logitistic regression analysis was used to determine the relationship between ISS and return to play. Subgroup analysis was performed on patients participating in high level athletic activity (pre-injury Tegner >= 7) an those participating in only recreational or low level activity (pre-injury Tegner <7).Results:A total of 36 patients (mean 35 years, 72% male) completed the study protocol at a mean 1.8 years post-op (range 1 year to 3.6 years). Logistic regression revealed no association between ISS and return to play in the complete cohort. Subgroup analysis revealed that for 20 patients who had participated in high level competitive athletics prior to injury (Pre-injury Tegner >= 7), for every 16 point increase in ISS, the odds ratio for return to same level of play was 8.3 (p=0.055) and the OR for return to within 1 Tegner level of play was 6.3 (p=0.043). There was no association between ISS and return to previous activity in the 16 patients with lower pre-injury levels of activity.Conclusion:Improved ankle strength was associated with return to previous level of activity only in patients who participate in high level athletic activity. These results suggest that patients with more strenuous athletic activity prior to injury are more dependent on recovery of ankle strength in the post-operative time period in order to return to their previous high level of play. In contrast, regaining strength may be less important for returning to normal activities for less active patients.