Non-injured Leg Research Articles

Impact of Physiotherapy on the Calf Muscle Torque Variability after Achilles Tendon Rupture

It has been established that muscle torque variability determines movement stability during the task [1]. Calf muscle weakness, ankle range of motion reduction and postural misbalance are common pathological limitations after Achilles tendon rupture (ATR). Most studies analyse rehabilitation influence for muscle strength and body balance, but there is a lack of information about calf muscle torque variability. The aim of the study was to determine ankle plantar flexion and dorsal flexion muscle maximal voluntary contraction torque and variability Q. Organization and methods. We measured five males, (aged 29 ± 6) after 6.5 – week surgery of ATR. Participants performed isometric ankle flexion and extension force with injured and non-injured legs. Muscles maximal voluntary contraction (MVC) torque and torque variability were measured at –15°; 0°; 15° angles. The variability of target force was 20% of MVC torque. Rehabilitation programme consisted of balance, muscle strength and stretching exercises. Calf muscle MVC torque and variability were observed before and after 8-week rehabilitation. The results of the research. We determined that after physiotherapy the injured and the non-injured leg isometric ankle flexion and extension muscle MVC torque increased and muscle torque variability decreased.Keywords: muscle torque variability, isometric maximal voluntary contraction torque, rehabilitation suformavimas.

Early tibial subchondral bone texture changes after arthroscopic partial meniscectomy in knees without radiographic OA: A prospective cohort study.

Arthroscopic partial meniscectomy (APM) may lead to changes in underlying trabecular bone (TB) structure potentially promoting the development of knee joint osteoarthritis. Our aim was to investigate if there are early changes occurring in tibial subchondral TB texture in the leg undergoing medial APM compared with the unoperated non-injured contra-lateral leg. The bone texture was measured as the medial-to-lateral ratio of fractal dimensions (FD) calculated for regions selected on weight-bearing anteroposterior tibiofemoral x-rays. Twenty-one subjects before and 12 months after APM were included from 374 patients scheduled for unilateral medial APM. The medial-to-lateral ratio was calculated for horizontal, vertical, and roughest FDs respectively. Higher FD means higher bone roughness. Each FD was calculated over a range of scales using a variance orientation transform method. Mean values of medial-to-lateral horizontal FD calculated for APM knees at follow-up were higher than those at baseline. For unoperated knees the values were lower. The difference in the horizontal FD change from baseline to follow-up between APM and contra-lateral legs was 0.028 (95% CI, 0.004-0.052). The bone roughness changes may reflect the increase in peak knee adduction moment (KAM) and KAM impulse during walking reported for the same cohort in a previous study. They may also reflect early signs of osteoarthritis development and thus, we speculate that individuals with increased bone texture roughness ratio after APM might be at higher risk of knee osteoarthritis development.

Single-Leg Roman Chair Hold Is More Effective Than the Nordic Hamstring Curl in Improving Hamstring Strength-Endurance in Gaelic Footballers With Previous Hamstring Injury.

Macdonald, B, O'Neill, J, Pollock, N, and Van Hooren, B. Single-leg Roman chair hold is more effective than the Nordic hamstring curl in improving hamstring strength-endurance in Gaelic footballers with previous hamstring injury. J Strength Cond Res 33(12): 3302-3308, 2019-Poor hamstring strength-endurance is a risk factor for hamstring injuries. This study investigated the effectiveness of the single-leg Roman hold and Nordic hamstring curl in improving hamstring strength-endurance. Twelve Gaelic footballers (mean ± SD age, height, and mass were 25.17 ± 3.46 years, 179.25 ± 5.88 cm, 85.75 ± 4.75 kg, respectively) with a history of hamstring injury were randomized into 2 groups that performed 6 weeks of either Nordic hamstring curl or single-leg Roman chair hold training. The single-leg hamstring bridge (SLHB) was measured before and after intervention. The Roman chair group showed a very likely moderate magnitude improvement on SLHB performance for both legs (23.7% for the previously injured leg [90% confidence interval 9.6-39.6%] and 16.9% for the noninjured leg [6.2-28.8%]). The Nordic curl group showed a likely trivial change in SLHB performance for the noninjured leg (-2.1% [-6.7 to 2.6%]) and an unclear, but possibly trivial change for the previously injured leg (0.3% [-5.6 to 6.6%]). The Roman chair group improved very likely more with a moderate magnitude in both the noninjured (19.5% [8.0-32.2%]) and the previously injured leg (23.3% [8.5-40.0%]) compared with the Nordic curl group. This study demonstrated that 6-week single-leg Roman chair training substantially improved SLHB performance, suggesting that it may be an efficacious strategy to mitigate hamstring (re-) injury risk. Conversely, 6-week Nordic curl training did not substantially improve SLHB performance, suggesting this may not be the intervention of choice for modifying this risk factor.

A Novel Approach to Investigate Running Kinematics in Achilles Tendinopathy Patients Using Inertial Sensors

Mid-portion Achilles tendinopathy (AT) is a common injury in runners. Overloading the tendon results in pain, swelling and impaired running performance. Recovery involves rest and a gradual build up. Determining whether patients can resume training is difficult and currently rather qualitative. To provide quantitative data to the physician to assist clinical decision- making, we studied the between leg differences in running kinematics for AT patients using inertial sensors in the clinical setting. PURPOSE:To investigate lower limb kinematics in AT patients during 5 minute treadmill running in the clinic, using inertial magnetic measurement units (IMUs). METHODS:4 runners diagnosed with mild unilateral AT (4M , 48.8 ± 7.5 yrs, 188.8 ± 11.2 cm, 82.5 ± 11.1 kg) performed a 5 min. treadmill run in the sports medicine clinic, as part of a larger study, with 8 IMU’s at the feet, tibia, upper legs, sacrum and sternum. Ankle and knee angles were determined at initial contact (IC) and mid stance (MS). Additional parameters that were calculated were the vertical lower leg angle at IC (VLL), peak tibial impact (PTA), peak sacral impact (PSA), push-off power (POP) (lin. velocity at toe off, TO) and internal rotation (IR) of the tibia (at TO). Parameters were determined for the injured and non-injured leg at 1-min. intervals. An independent Mann-Whitney U-test was used to test for differences within patients between the injured and non-injured leg. RESULTS: Table 1 CONCLUSIONS:The injured leg of these AT patients showed significantly different running kinematics. AT strongly affected ankle mechanics, possibly as a compensatory strategy, indicating non-full recovery of the patients. The use of IMUs to determine the recovery of AT patients quantitatively is promising. Using IMUs there is no need for 3d optical motion capture systems or an instrumented treadmill to quantify running kinematics. Future research should follow up on these measurements to identify fully recovered patients.Table 1: Mean values ± standard deviation of the selected outcome parameters. Statistical differences was tested for using an independent Mann-Whitney-U-test.

Acute and Long-Term Effects of Mechanotherapy on the Outcome After an Achilles Repair: A Prospective Cohort Study With Historical Controls

ObjectivesTo evaluate the effects of vibration on Achilles’ tendon microcirculation and characteristics following surgical repair of Achilles’ tendon rupture. DesignCohort study with historical controls. SettingA university institute. ParticipantsParticipants (N=32), including 19 (16 men, 3 women; median [range] age: 43.0 [25.0-57.0] years) and 13 (10 men, 3 women; 44.00 [29.0-60.0] years) in the vibration (application to the ball of the foot, 30Hz, 2mm amplitude, 4kg pressure, and self-administration) and control groups, respectively, who underwent unilateral Achilles’ tendon repairs were recruited. InterventionA 4-week vibration intervention in the vibration group. Main Outcome MeasurementsThe tendon microcirculation was measured after the first session of vibration. The participants were evaluated repeatedly with bilateral follow-up measurements of tendon stiffness, 3 functional outcome tests, and a questionnaire survey. ResultsAcute effects of the vibration were observed immediately after the 5-minute vibration (P≤.001). Lower total hemoglobin and oxygen saturation were respectively observed (P=.043) in the repaired legs 3 and 6 months postsurgery in the vibration group as compared with the control group. The vibration group also showed greater tendon stiffness, heel raising height and hopping distance 3 or 6 months postoperation in both the repaired and noninjured legs (all P<.05). The microcirculatory characteristics 2 months postoperation were correlated with the outcomes at 6 months postoperation. ConclusionsDifferences in microcirculatory characteristics and better rehabilitation outcomes were observed in the legs with an Achilles repair that underwent the early vibration intervention.

Neuromuscular control in patients with acute ACL injury during stair ascent – A pilot study

Summary Background Studies showed altered kinematics and kinetics in anterior cruciate ligament (ACL) deficient participants, attributed to an altered sensorimotor control. However, literature on neuromuscular deficits is limited, thus the objective was to investigate the neuromuscular activity during stair ascent in patients with acute ACL rupture. Material and methods The activity of the M. vastus medialis (VM) and lateralis (VL), M. biceps femoris (BF) and M. semitendinosus (ST) was recorded using surface electromyography (EMG) in 9 acute ACL deficient (ACL-D) (rupture 1–3 weeks prior to test) and 9 ACL intact (ACL-I) matched subjects. Participants ascended 20 times a 6-step stair at self-selected speed. The movement was divided into pre-activation (PRE), weight-acceptance (WA) and push-off (PO) phase. Comparisons were made between the deficient leg of ACL-D and the matched uninjured leg of the ACL-I, as well as between the injured and non-injured leg of the ACL-D group. Results ACL-D showed in all muscles a reduced activation (ca. 50%, p Conclusions Altered activity during PRE indicates an alteration in the motor program (“pre-programmed activity”). Small differences in the intra-individual comparison showed bilateral consequences following ACL injury. Level of Evidence 3

Body Composition and Strength Parameters in Elite Judo Athletes 5 Years after Anterior Cruciate Ligament Reconstruction.

The purpose of this study was to investigate if there are still deficits in muscle mass or strength capabilities in elite judo athletes with a history of anterior cruciate ligament reconstruction (ACLR) after their return to the sport. Therefore, bioimpedance analysis, 3D-laser thigh circumference measurement and isokinetic dynamometry in a closed kinetic chain were used. The side-to-side differences were investigated in a group of judo athletes 5 years after ACLR (n=17) and compared with a group of healthy judo athletes (n=27). Neither thigh circumferences, nor muscle masses of the lower extremities differed in formerly injured judo athletes compared to healthy judo athletes. In contrast, isokinetic strength testing showed a significantly larger side-to-side difference of peak muscle force in formerly injured judo athletes (p=0.021). They provided significantly lower peak forces with the formerly injured leg than with the non-injured leg (p<0.001). The authors conclude that strength capabilities, but not body composition, remains altered in recovered judo athletes in mean 5 years after ACLR and definitely after their return to sports. This indicates that the focus of rehabilitation protocols and return to sports assessments should focus more on maximum strength capabilities.

Hamstrings and Quadriceps Muscles Function in Subjects with Prior ACL Reconstruction Surgery.

Background: As the knee joint is a common site for injury among younger people, the purpose of this study was to measure the skeletal muscle endurance and strength on people with prior anterior cruciate ligament (ACL) knee reconstruction surgery. Method: Young healthy female subjects who reported having knee reconstruction surgery more than one-year prior were tested. The skeletal muscle endurance index (EI) of the hamstrings and quadriceps muscles was determined as the decline in the specific muscle acceleration in response to 2 Hz, 4 Hz, and 6 Hz electrical stimulation. Maximal isometric muscle strength (MVC) was measured in the hamstrings and quadriceps muscles. Results: The hamstrings muscles in the injured leg had less endurance than the non-injured leg at 6 Hz stimulation (55.5 ± 13.2% versus 78.0 ± 13.3%, p < 0.01). Muscle endurance was not reduced in the quadriceps muscles in the injured leg compared to the non-injured leg at 6 Hz stimulation (78.0 ± 13.3% versus 80.3 ± 10.0%, p = 0.45). There were no differences in MVC between the injured and non-injured legs for either the hamstrings (p = 0.20) or quadriceps muscles (p = 0.67). Conclusions: Muscle endurance was reduced in the hamstrings muscles at least one-year post injury, while hamstrings strength was recovered. Reduced hamstrings muscle endurance could be a result of lack of endurance training during rehabilitation. This may contribute to re-injury in the muscle, even in people who have recovered muscle strength.

Cross-education does not improve early and late-phase rehabilitation outcomes after ACL reconstruction: a randomized controlled clinical trial.

Limited evidence suggests that cross-education affords clinical benefits in the initial 8weeks after anterior cruciate ligament (ACL) reconstruction, but it is unknown if such cross-education effects are reproducible and still present in later phases of rehabilitation. We examined whether cross-education, as an adjuvant to standard therapy, would accelerate the rehabilitation up to 26weeks after ACL reconstruction by attenuating quadriceps weakness. ACL-reconstructed patients were randomized into experimental (n = 22) and control groups (n = 21). Both groups received standard care after ACL reconstruction. In addition, the experimental group strength trained the quadriceps of the non-operated leg during weeks 1-12 after surgery (i.e., cross-education). Self-reported knee function was assessed with the Hughston Clinic Knee score as the primary outcome. Secondary outcomes were maximal quadriceps and hamstring strength and single leg hop distance. All outcomes were measured 29 ± 23days prior to surgery, as a reference, and at 5-week, 12-week, and 26-week post-surgery. Both groups scored 12% worse on self-reported knee function 5-week post-surgery (95% CI 7-17) and showed 15% improvement 26-week post-surgery (95% CI - 20 to - 10). No cross-education effect was found. Interestingly, males scored 8-10% worse than females at each time point post-surgery. None of 33 secondary outcomes showed a cross-education effect. At 26-week post-surgery, both legs improved maximal quadriceps (5-14%) and hamstring strength (7-18%), and the non-injured leg improved 2% in hop distance. The ACL recovery was not affected by limb dominance and age. 26weeks of standard care improved self-reported knee function and maximal leg strength relative to pre-surgery and adding cross-education did not further accelerate ACL recovery. I. This randomized controlled clinical trial is registered at the Dutch trial register ( http://www.trialregister.nl ) under NTR4395.

Greater loss of horizontal force after a repeated-sprint test in footballers with a previous hamstring injury

ObjectivesTo quantify changes in running kinetics and kinematics during a repeated-sprint test in football players, and explore the sensitivity and specificity with which these variables can identify previous hamstring injury. Design20 Western Australia State League footballers with previous unilateral hamstring injury and 20 players without completed a 10×6-s repeated-sprint test on a non-motorised treadmill dynamometer. MethodsChanges in horizontal force, vertical force, contact time and flight time were compared between previously injured and uninjured legs of participants. ResultsMean horizontal force production of the previously injured leg in the injured group was 13% lower (p=0.001), and this magnitude of change was used to identify the injured legs within the cohort with 77% specificity and 85% sensitivity. Furthermore, the area under the Receiver Operating Characteristics curve (0.846) demonstrated that the between-leg difference in mean horizontal force was a good instrument for identifying previous hamstring injury. ConclusionsThere is a greater fatigued-induced change in mean horizontal force during a repeated-sprint test in legs with previous hamstring injury than the non-injured legs of the injured players or the legs of uninjured players. Such asymmetry may contribute to impaired performance in football players returning from hamstring injury and also to the high rate of hamstring re-injury. Rehabilitation and return-to-play strategies should emphasise a reduction in asymmetry, particularly during repeated high-intensity efforts. Furthermore, binary regression and Receiver Operating Characteristic analyses suggest that changes in mean horizontal force could be used to assess risk of hamstring injury, re-injury and/or return to play.

Cross-education does not accelerate the rehabilitation of neuromuscular functions after ACL reconstruction: a randomized controlled clinical trial

PurposeCross-education reduces quadriceps weakness 8 weeks after anterior cruciate ligament (ACL) surgery, but the long-term effects are unknown. We investigated whether cross-education, as an adjuvant to the standard rehabilitation, would accelerate recovery of quadriceps strength and neuromuscular function up to 26 weeks post-surgery.MethodsGroup allocation was randomized. The experimental (n = 22) and control (n = 21) group received standard rehabilitation. In addition, the experimental group strength trained the quadriceps of the non-injured leg in weeks 1–12 post-surgery (i.e., cross-education). Primary and secondary outcomes were measured in both legs 29 ± 23 days prior to surgery and at 5, 12, and 26 weeks post-surgery.ResultsThe primary outcome showed time and cross-education effects. Maximal quadriceps strength in the reconstructed leg decreased 35% and 12% at, respectively, 5 and 12 weeks post-surgery and improved 11% at 26 weeks post-surgery, where strength of the non-injured leg showed a gradual increase post-surgery up to 14% (all p ≤ 0.015). Limb symmetry deteriorated 9–10% more for the experimental than control group at 5 and 12 weeks post-surgery (both p ≤ 0.030). One of 34 secondary outcomes revealed a cross-education effect: Voluntary quadriceps activation of the reconstructed leg was 6% reduced for the experimental vs. control group at 12 weeks post-surgery (p = 0.023). Both legs improved force control (22–34%) and dynamic balance (6–7%) at 26 weeks post-surgery (all p ≤ 0.043). Knee joint proprioception and static balance remained unchanged.ConclusionStandard rehabilitation improved maximal quadriceps strength, force control, and dynamic balance in both legs relative to pre-surgery but adding cross-education did not accelerate recovery following ACL reconstruction.

Altered movement during single leg hop test after ACL reconstruction: implications to incorporate 2-D video movement analysis for hop tests

PurposeThere is a lack of objective factors which can be used in guiding the return to sport (RTS) decision after an anterior cruciate ligament reconstruction (ACLR). The purpose of the current study was to conduct qualitative analysis of the single leg hop (SLH) in patients after ACLR with a simple and clinical friendly method and to compare the possible difference in movement pattern between male and female patients.MethodsSixty-five patients performed the single leg hop (SLH) test at 6.8 ± 1.0 months following isolated ACLR. Digital video camcorders recorded frontal and sagittal plane views of the patient performing the SLH. Knee flexion at initial contact (IC), peak knee flexion, knee flexion range of motion (RoM), and knee valgus RoM were calculated. In addition, limb symmetry index (LSI) scores were calculated.ResultsNo differences were found in movement pattern between males and females. Movement analysis revealed that males had a decrease in knee flexion at IC (p = 0.018), peak knee flexion (p = 0.002), and knee flexion RoM (p = 0.017) in the injured leg compared to the non-injured leg. Females demonstrated a decrease in peak knee flexion (p = 0.011) and knee flexion RoM (p = 0.023) in the injured leg compared to the non-injured leg. Average LSI scores were 92.4% for males and 94.5% for females.ConclusionsAlthough LSI scores were > 90%, clinical relevant altered movement patterns were detected in the injured leg compared to the non-injured leg. Caution is warranted to solely rely on LSI scores to determine RTS readiness.Clinical trial registry name and registrationThe University of Groningen, ID 2012.362.Level of evidenceIII.

Curve analyses reveal altered knee, hip, and trunk kinematics during drop–jumps long after anterior cruciate ligament rupture

BackgroundAnterior cruciate ligament (ACL) ruptures may lead to knee dysfunctions later in life. Single-leg tasks are often evaluated, but bilateral movements may also be compromised. Our aim was to use curve analyses to examine double-leg drop–jump kinematics in ACL-reconstructed, ACL-deficient, and healthy-knee cohorts. MethodsSubjects with unilateral ACL ruptures treated more than two decades ago (17–28years) conservatively with physiotherapy (ACLPT, n=26) or in combination with reconstructive surgery (ACLR, n=28) and healthy-knee controls (n=25) performed 40-cm drop–jumps. Three-dimensional knee, hip, and trunk kinematics were analyzed during Rebound, Flight, and Landing phases. Curves were time-normalized and compared between groups (injured and non-injured legs of ACLPT and ACLR vs. non-dominant and dominant legs of controls) and within groups (between legs) using functional analysis of variance methods. ResultsCompared to controls, ACL groups exhibited less knee and hip flexion on both legs during Rebound and greater knee external rotation on their injured leg at the start of Rebound and Landing. ACLR also showed less trunk flexion during Rebound. Between-leg differences were observed in ACLR only, with the injured leg more internally rotated at the hip. Overall, kinematic curves were similar between ACLR and ACLPT. However, compared to controls, deviations spanned a greater proportion of the drop–jump movement at the hip in ACLR and at the knee in ACLPT. ConclusionsTrunk and bilateral leg kinematics during double-leg drop–jumps are still compromised long after ACL-rupture care, independent of treatment. Curve analyses indicate the presence of distinct compensatory mechanisms in ACLPT and ACLR compared to controls.

Isokinetic Extension Strength Is Associated With Single-Leg Vertical Jump Height.

Background:Isokinetic strength testing is an important tool in the evaluation of the physical capacities of athletes as well as for decision making regarding return to sports after anterior cruciate ligament (ACL) reconstruction in both athletes and the lay population. However, isokinetic testing is time consuming and requires special testing equipment.Hypothesis:A single-jump test, regardless of leg dominance, may provide information regarding knee extension strength through the use of correlation analysis of jump height and peak torque of isokinetic muscle strength.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 169 patients who underwent ACL reconstruction were included in this study. Isokinetic testing was performed on the injured and noninjured legs. Additionally, a single-leg countermovement jump was performed to assess jump height using a jump accelerometer sensor. Extension strength values were used to assess the association between isokinetic muscle strength and jump height.Results:The sample consisted of 60 female (mean age, 20.8 ± 8.3 years; mean weight, 61.7 ± 6.5 kg; mean height, 167.7 ± 5.3 cm) and 109 male (mean age, 23.2 ± 7.7 years; mean weight, 74.6 ± 10.2 kg; mean height, 179.9 ± 6.9 cm) patients. Bivariate correlation analysis showed an association (r = 0.56, P < .001) between jump height and isokinetic extension strength on the noninvolved side as well as an association (r = 0.52, P < .001) for the involved side. Regression analysis showed that in addition to jump height (beta = 0.49, P < .001), sex (beta = –0.17, P = .008) and body mass index (beta = 0.37, P < .001) affected isokinetic strength. The final model explained 51.1% of the variance in isokinetic muscle strength, with jump height having the strongest impact (beta = 0.49, P < .001) and explaining 31.5% of the variance.Conclusion:Initial analysis showed a strong association between isokinetic strength and jump height. The study population encompassed various backgrounds, skill levels, and activity profiles, which might have affected the outcome. Even after controlling for age and sex, isokinetic strength was still moderately associated with jump height. Therefore, the jump technique and type of sport should be considered in future research.

Altered long-term health-related quality of life in patients following patella fractures: a long-term follow-up study of 49 patients.

The primary aim was to investigate the health-related quality of life (HRQOL) in patients treated for a patella fracture. The explorative aim was to report the associations between HRQOL, knee osteoarthritis, muscle strength and gait function. The study design was a cohort study. Patients who were treated for patella fractures at Aalborg University Hospital, Denmark between January 2006 and December 2009 were identified. Patients between the age of 18 and 80 were included. The main outcome was assessed by the EQ5D-5L questionnaire. Classifications by Sperner and Kellgren/Lawrence were applied to evaluate osteoarthritis. Moreover, functional outcomes were evaluated by: KOOS, muscle strength and gait analysis. Forty-nine patients were included with a mean follow-up time of 8.5years. The mean age was 53.9years. The mean EQ5D-5L index value was 0.741, and was significantly worse compared to a reference population. X-rays taken at the time of diagnosis and the time of follow-up showed progression towards a higher degree of osteoarthritis in the injured knee for both the patellofemoral and tibiofemoral joints. Patients demonstrated significantly lower knee extension strength in the injured leg compared to the non-injured leg (P = 0.011). No significant difference in gait speed and cadence were observed compared to the reference population. Knee osteoarthritis, muscle strength and gait patterns were not associated with HRQOL (R < 0.35). At 8.5years following a patella fracture, HRQOL was significantly worse compared to an age-matched reference population.

Motor asymmetry associated with anterior cruciate ligament rupture

Functional knee instability due to rupture of the anterior cruciate ligament (ACL), is difficult to measure in the clinic setting, thereby limiting the monitoring of deficiencies and the choice of treatments. This prospective and observational study aims to quantify the motor asymmetry associated with knee instability after ACL rupture, over ambulation tasks on forceplates. Five subjects with ACL rupture occurring in the 2 months before enrolment (ACL group, 5F, age 24 ± 3) and five healthy subjects (control group, CTL, age 24 ± 5) paired by age and sex, were evaluated barefoot using six forceplates in a movement analysis laboratory. All participants performed linear displacements at comfortable and fast walking speed as well as slow running (3 × 6 meters/task), angular displacements with lateral and medial rotations (3 trials/side/task), and bipodal (3 trials) and unipodal jumps (3 trials/side). Nine temporal and dynamic parameters were bilaterally measured: duration of stance (tstance), flight (tflight), reception (treception) and propulsion (tpropulsion), maximal ground reaction force in medial, lateral, anterior, posterior, and vertical directions (respectively, Fmed, Flat, Fant, Fpos, Fver), and root mean square of the vertical ground reaction force moment (Mz). For each parameter, we calculate the asymmetry index, defined as the difference between the dominant and the non-dominant legs in CTL and between the injured and non-injured legs in ACL divided by the dominant or non-injured side. Mann-Whitney tests were used to compare asymmetry between ACL and CTL (significance, P < 0.05). The asymmetry index was higher in ACL compared with CTL for tstance in fast walking speed ( P = 0.009), tflight in bilateral jump ( P = 0.07), Fver in comfortable walking speed ( P = 0.02) and in unipodal jump (p = 0.02) and Flat in angular displacement with lateral rotation ( P = 0.07). Others results were non-significant. Functional ambulation tasks in the lab, including fast ambulation and jumps, using force plates, may provide objective quantification of temporal and dynamic asymmetry associated with ACL rupture.

Testosterone Supplementation Increases Lean Mass in Men Undergoing Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Objectives:Surgical reconstruction of the anterior cruciate ligament (ACL) is essential for those who wish to resume athletic activity following ACL rupture. However, the trauma of surgical repair and post-operative immobility can exacerbate muscle loss and strength. This study investigated the effect of perioperative testosterone administration on lean mass recovery following ACL reconstruction in men. The effects of testosterone on leg strength and clinical outcome scores were also investigated. We hypothesized that testosterone would increase lean mass and leg strength, and improve clinical outcome scores 6 and 12 weeks after surgery to a greater degree than placebo.Methods:This was a randomized, controlled, double blinded clinical trial comparing testosterone and placebo for recovery from ACL repair. Thirteen male subjects scheduled for ACL reconstruction were randomized into two groups, testosterone (n=6) and placebo (n=7). Participants in the testosterone group received 200 mg of testosterone administration weekly for 8 weeks starting 2 weeks prior to surgery. Participants in the control group received a saline placebo intramuscularly following the same schedule. Both intervention groups underwent standard physical rehabilitation. The primary outcome was change in total lean body mass at 6 and 12 weeks, measured by whole-body dual-energy x-ray absorptiometry. Secondary outcomes were extensor muscle strength measured using a Cybex Dynamometer, and the Tegner Activity Score (TAS) and Knee Injury and Osteoarthritis Outcome Score (KOOS).Results:Total testosterone levels in the blood increased from baseline to an average of 860 ± 254 ng/dL by 1 day prior to surgery and 746 ± 173 ng/dL at 6 weeks post-surgery for the testosterone group. The differences in serum testosterone levels between the placebo and testosterone groups at 1 day prior to surgery and 6 weeks post-surgery were both statistically significant (p<0.001). We found that testosterone increased lean mass by 2.8 ± 1.7 kg from baseline at 6 weeks following surgery, while the placebo group had a decrease in lean muscle mass of 0.1 ± 1.5 kg (p=0.01) (Figure 1). Extensor strength of the non-injured leg had a greater increase from baseline in the testosterone group (20.8 ± 25.6 Nm) than the placebo group (-21.4 ± 36.7 Nm) at 12 weeks (p=0.02). There were no significant differences in injured leg strength or clinical outcome scores throughout the study period.Conclusion:Despite a catabolic environment, acute testosterone supplementation increased lean mass 6 weeks after ACL reconstruction, and strength of the non-injured leg 12 weeks after surgery, to a greater degree than placebo. These results suggest that testosterone may be a novel, useful adjunct to physical therapy for knee surgery rehabilitation by offsetting perioperative muscle loss from surgery and immobility. Larger studies are now necessary to elucidate the effects of perioperative testosterone administration on injured leg strength and clinical outcomes following surgery.

Asymmetry in gait pattern following bicondylar tibial plateau fractures—A prospective one-year cohort study

IntroductionDespite the high number of studies evaluating outcomes following tibial plateau fractures, the literature lacks studies including the objective assessment of gait pattern. The purpose of the present study was to evaluate asymmetry in gait patterns at 12 months after frame removal following ring fixation of a tibial plateau fracture. Patients and methodsThe study design was a prospective cohort study. The primary outcome measurement was the gait patterns 12 months after frame removal measured with a pressure-sensitive mat. The mat registers footprints and present gait speed, cadence, as well as temporal and spatial parameters of the gait cycle. Gait patterns were compared to a healthy reference population. ResultsTwenty-three patients were included with a mean age of 54.4 years (32–78 years). Patients presented with a shorter step-length of the injured leg compared to the non-injured leg (asymmetry of 11.3%). Analysis of single-support showed shorter support time of the injured leg compared to the non-injured leg (asymmetry of 8.7%). Moreover, analysis of swing-time showed increased swing-time of the injured leg (asymmetry of 8.9%). Compared to a healthy reference population, increased asymmetry in all gait patterns was observed. The association between asymmetry and health-related quality of life (HRQOL) showed moderate associations (single-support: R=0.50, P=0.03; step-length: R=0.43, P=0.07; swing-time: R=0.46, P=0.05). ConclusionCompared to a healthy reference population, gait asymmetry is common 12 months after frame removal in patients treated with external ring fixation following a tibial plateau fracture of the tibia.

Knee function among elite handball and football players 1-6years after anterior cruciate ligament injury.

The aim of the study was to describe objective and self-reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non-injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non-injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1-6years post-injury (3.5±2.5years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL-injured (N=80) and non-injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2-9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3-8.1) were observed in previously ACL-injured legs compared to the non-injured contralateral side (N=80). ACL-injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8-26) and healthy knees (N=1556, 23%, 95% CI: 14-33). KOOS scores were significantly lower for injured knees compared to knees of non-injured players. ACL-injured players who have successfully returned to elite sport have comparable strength and balance measures as their non-injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.

High-Grade Partial and Retracted (&lt;2 cm) Proximal Hamstring Ruptures

Background:High-grade partial proximal hamstring tears and complete tears with retraction less than 2 cm are a subset of proximal hamstring injuries where, historically, treatment has been nonoperative. It is unknown how nonoperative treatment compares with operative treatment.Hypothesis:The clinical and functional outcomes of nonoperative and operative treatment of partial/complete proximal hamstring tears were compared. We hypothesize that operative treatment of these tears leads to better clinical and functional results.Study Design:Case series; Level of evidence, 4.Methods:A retrospective review identified patients with a high-grade partial or complete proximal hamstring rupture with retraction less than 2 cm treated either operatively or nonoperatively from 2007 to 2015. All patients had an initial period of nonoperative treatment. Surgery was offered if patients had continued pain and/or limited function refractory to nonoperative treatment with physical therapy. Outcome measures were each patient’s strength perception, ability to return to activity, Lower Extremity Functional Scale (LEFS) score, Short Form–12 (SF-12) physical and mental component outcome scores, distance traversed by a single-leg hop, and Biodex hamstring strength testing.Results:A total of 25 patients were enrolled in the study. The 15 patients who were treated nonoperatively sustained injuries at a mean age of 55.73 ± 14.83 years and were evaluated 35.47 ± 30.35 months after injury. The 10 patients who elected to have surgery sustained injuries at 50.40 ± 6.31 years of age (P = .23) and were evaluated 30.11 ± 19.43 months after surgery. LEFS scores were significantly greater for the operative group compared with the nonoperative group (77/80 vs 64.3/80; P = .01). SF-12 physical component scores for the operative group were also significantly greater (P = .03). Objectively, operative and nonoperative treatment modalities showed no significant difference in terms of single-leg hop distance compared with each patient’s noninjured leg (P = .26) and torque deficit at isokinetic speeds of 60 and 180 deg/s (P = .46 and .70, respectively).Conclusion:Patients who undergo operative and nonoperative treatment of high-grade partial and/or complete proximal hamstring tears with <2 cm retraction demonstrate good clinical and functional outcomes. In our series, 40% of patients treated nonoperatively with physical therapy went on to have surgery. For those patients with persistent pain and/or loss of function despite conservative treatment, surgical repair is a viable treatment option that is met with good results.