Limb Symmetry Index Research Articles

Retrospective Study from a Single Center in Poland of Postoperative Outcomes of Muscle Strength in Patients After Surgical Suturing of the Achilles Tendon Using a Kessler's Suture and 28 Weeks of Supervised Postoperative Physiotherapy.

BACKGROUND A retrospective study from a single center in Poland was aimed to evaluate the effect of 47 supervised physiotherapy (SVPh) visits on relative peak torque (RPT) and relative isometric torque (RIT) of foot plantar flexion muscles (FPFM) and foot dorsiflexion muscles (FDFM) with a frequency of 1.7 visits per week conducted for 28 weeks after surgical suturing of the Achilles tendon using a Kessler's suture (ATSSKS). We hypothesized a higher number, frequency, and intensity of supervised physiotherapy visits (HNFISVPhVs) would correlate with and significantly improve RIT and RPT for FPFM. MATERIAL AND METHODS Group A included 20 patients (x=47 visits) after ATSSKS with one SVPh protocol who were divided into subgroups: with HNFISVPhVs (x=72) and with a lower number, frequency, and intensity of SVPh visits (LNFISVPhVs, x=33). Twenty participants without Achilles tendon rupture were included in group B (control). Both groups (≥7 Tegner activity scale) underwent RIT, RPT, and Limb Symmetry Index (LSI) measurements using Biodex Medical System 3. RESULTS FPFM RIT were significantly lower in operated limbs in group A than for non-operated limbs in group B (P≤0.001). HNFISVPhVs correlated with higher FPFM RIT and LSI in operated limbs (from r=0.444, P=0.05 to r=0.585, P=0.007). HNFISVPhVs obtained higher LSI of FPFM RPT of 180°/s (P=0.022) and 30°/s (P=0.049) than LNFISVPhVs. CONCLUSIONS SVPh with 47 visits after ATSSKS for 28 weeks was insufficient to obtain equal values of RIT for FPFM and FDFM, but HNFISVPhVs correlated with higher RIT values and considerably improved RIT and RPT for FPFM compared with LNFISVPhVs.

Psychological readiness at 9 months after anterior cruciate ligament reconstruction –which factors affect?

ObjectiveTo investigate the association of psychological readiness at 9 months after anterior cruciate ligament reconstruction (ACLR) with knee strength and range-of-motion (ROM) at 3 and 9 months postoperatively. DesignRetrospective cohort study. SettingPrivate orthopedic hospital. ParticipantsSeventy-eight patients after ACLR. Main outcomes measuresThe participants completed the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale as an assessment of psychological readiness at 9 months after ACLR. Isometric and isokinetic quadriceps and hamstring strength were measured by a dynamometer at 3 and 9 months postoperatively. Knee extension and flexion ROM were measured in 5° increments with a standard goniometer at 3 and 9 months postoperatively. ResultsUnivariate regression analysis showed that age, limb symmetry index (LSI) of quadriceps strength at 3 and 9 months, and knee extension ROM deficit (>5°) at 3 and 9 months were associated with ACL-RSI scores at 9 months (P < 0.05). Age and LSI of quadriceps strength at 3 months remained significant predictors of ACL-RSI scores at 9 months in multiple regression analysis (R2 = 0.20, P < 0.001). ConclusionsEarly improvements in quadriceps strength after ACLR may have a positive impact on psychological readiness at 9 months postoperatively.

Muscle activation timing and knee biomechanics during single leg hop in subjects with and without anterior cruciate ligament reconstruction: a case study

The Single Leg Hop test (SLHT) is commonly performed to determine readiness to return to sport (RTS) after anterior cruciate ligament (ACL) injury and reconstruction [1]. Usually, the between-limb symmetry of hop distance is considered as a criterion to clear the athletes to RTS. However, athletes may pass this criterion despite ongoing biomechanical and neuromuscular deficits. Several works developed an instrumented approach of the SLHT to assess biomechanical parameters associated to ACL injury risk [1]. Although it is known that muscle pre-activation timing during landing can be altered in patients with ACL reconstruction (ACLR) [2], thus exposing them to a reinjury risk, very few studies have related biomechanical parameters with electromyographic (EMG) signals of the involved muscles. The aim of this preliminary study is to assess muscle pre-activation timing prior to SLHT landing in both ACLR and HC athletes and to associate this information with ACL injury-related kinematic and kinetic parameters. Two male soccer athletes (Tegner Activity Score ≥ 6) participated in the study, one healthy (HC) and one with ACLR (12 months before the test; injured limb: left). They performed three SLHT landing on a force plate (AMTI, USA, 1000 Hz) after standardized warm-up. The 3D trajectories of 52 markers were measured by an optoelectronic system (Vicon, 200 Hz) [3]. Eight wireless bipolar EMG electrodes (MiniWave, Cometa, Italy) were placed on Vastus Medialis (VM), Vastus Laterialis (VL), Semitendinous (ST) and Biceps femoris (BF) on both limbs according to the SENIAM guidelines [4]. All instruments were electronically synchronized. Foot-force plate contact was identified by setting a threshold of 20 N on the vertical GRF (vGRF) [5]. EMG onset prior to landing was identified according to [2]. A set of ACL injury risk-related parameters were then extracted: peak vGRF (vGRF peak ), peak knee flexion and abduction moment (KMflex peak KMabd peak ), and knee flexion at initial contact (KflexIC). Also, for each SLHT, the hop distance was assessed (SLH dist ). The Limb Symmetry Index (LSI) was then calculated for each parameter. For each athlete and each limb, the SLH with the greater hopping distance was considered for further data processing. Muscle pre-activation timing was shorter in ACLR subject than HC in all muscles (Table 1). ACLR subject also showed higher values in peak knee moments, especially in the injured limb, as well as greater asymmetry for most of the investigated parameters, especially knee angles and moments. In the ACLR subject, the lower muscle pre-activation timing prior to landing may lead to an uncoordinated movement and to a deficit in muscle force generation to stabilize the joint, thus increasing knee injury risk [2]. This timing was even shorter in the injured limb. From a biomechanical point of view, a greater asymmetry was found in the ACLR subject with respect to the HC in both kinematic and kinetic parameters. On the contrary, hop distance LSI did not show any clear difference between the two participants. These results corroborate the hypothesis that evaluating only hop distance is reductive.

Isokinetic Evaluation in a Large Cohort of Normal Ankles

Category: Ankle; Sports; Other Introduction/Purpose: The isokinetic test has been used diffusely as a way to evaluate the functional results after the rehabilitation of musculoskeletal injuries. In the ankle, in particular, most studies are related to lateral ligament injuries and Achilles tendon's injuries. However, different protocols are used and a lack of normative values is observed in the literature. The aim of this work is to perform a global isokinetic evaluation on healthy ankles in order to propose reference values for future patients. Methods: We evaluated 100 participants (200 ankles) using the Biodex 3 System for the eversion, inversion, dorsiflexion and plantar flexion movements of the ankle. The sample consisted of individuals aged 20-60 years, with an active life and practice of recreational physical activity (non-athlete) and without previous injuries. Five repetitions for strength (N / m) and work (J) at a speed of 30o / sec and 10 repetitions for power (W) at a speed of 120o / sec were performed in our protocol. Agonist / antagonist ratio and the Muscle Deficiency Index, which globally assesses the balance between the sides for each movement, were also evaluated, as well as the demographic variables. Different statistical analyzes were performed for each parameter. Results: The mean age was 38.5 years and BMI 25.8 (CI 2.7 and 0.8 respectively) in 69 men and 31 women. In 78% of participants, the dominant ankle was the right one. The non-dominant side was consistently stronger (higher peak torque) in all movements (p&lt;0.001 - Wilcoxon Test). The mean values obtained for force in each movement were 29.9N/m for eversion, 34.8N/m (CI 1.6) for inversion, 48.6N/m (2.0) for dorsiflexion and 140.2 N/m for plantar flexion. Such parameters for men and women were also obtained (p&lt;0.001) and there was no correlation between age or BMI with the maximum torque (N/m) through Spearman's Correlation. The ratio of eversors / inverters was 88.8% (CI 3.1) and that of dorsiflexors / plantar flexors was 36.1% (1.3). Limb symmetry Index were &gt;= 90% between sides in all four moviments (91,99% for eversion, 98,57% for inversion, 96,96% for dorsiflexion and 94,72% for plantarflexion). Conclusion: The non-dominant side was stronger in this evaluation of the two hundred healthy ankles. However, this difference was within the expected range for the limb symmetry index and for the MDI, showing that limb dominance is not relevant for the isokinetic assessment of the ankle. In the studied sample, the demographic variables (except gender) did not show any correlation with the evaluated parameters, especially with the maximum torque. Normative values of torque forces and agonist/antagonist balances were proposed. The results have implications for rehabilitation protocols and criteria for returning to sports.

Effect of Radiological Evidence of Kaplan Fiber Injury on the Clinical and Functional Outcomes After Acute Anterior Cruciate Ligament Reconstruction

Background: A paucity of information is available regarding the clinical outcomes of patients with radiological evidence of Kaplan fiber (KF) injury who undergo anterior cruciate ligament (ACL) reconstruction (ACLR). Purpose/Hypothesis: The purpose was to compare clinical and functional outcomes in patients undergoing acute primary ACLR with and without magnetic resonance imaging (MRI) evidence of KF injury. The hypothesis was that there would be no difference in clinical or functional outcomes in patients with versus those without radiological evidence of KF injury. Study Design: Cohort study; Level of evidence, 3. Methods: MRI analysis was conducted on patients in a longitudinal prospective study of ACL injury. Only patients who had an MRI scan and had undergone isolated primary ACLR within 60 days of injury were included. MRI was performed using standard knee protocols, and diagnostic criteria were applied to identify KF injury. A total of 32 patients with KF injury (mean age, 24.2 years; 21 male, 11 female) were identified and matched for sex, age, graft type, and preinjury activity with 90 patients who had intact KF. Patients were followed up at 12 months with KT-1000 arthrometer measurements of side-to-side difference in anterior knee laxity, single- and triple-hop limb symmetry index (LSI), Marx activity and International Knee Documentation Committee (IKDC) scores, and return to sport (RTS) rates at 12 months and 24 months. Results: No differences were found in anterior knee laxity and single- and triple-hop LSI values between the KF-intact and KF-injured cohorts at 12 months. No differences in Marx and IKDC scores were found between the groups at 12 months and 2 years. The overall rate of RTS within 24 months was 75% (92/122), and 5 patients (2 KF-injured; 3 KF-intact) had a subsequent graft rupture. Conclusion: We found no difference in clinical or functional outcomes in patients with and without radiological evidence of KF injury who underwent acute primary ACLR. Based on these findings, the radiological presence of KF injury at the time of acute ACL injury should not be regarded as a risk factor for a negative prognosis after ACLR.

Isometric Knee Muscle Strength and Patient-Reported Measures Five Years after Anterior Cruciate Ligament Reconstruction: Comparison of Single versus Dual Autograft Hamstring Tendon Harvesting.

There is some controversy regarding the use of one or two hamstring tendons for anterior cruciate ligament reconstruction (ACLR). In this study, two cohorts of 22 male patients underwent an ACLR with hamstring tendon autografts. One cohort was reconstructed through an all-inside technique with the semitendinosus tendon (ST group) and the other with the semitendinosus and gracilis tendons (ST-G group). Anterior tibial translation (ATT), Lysholm, and IKDC scores were assessed preoperatively and five years postoperation. Additionally, isometric knee muscle strength was manually measured in both groups and in another cohort of 22 uninjured control male subjects five years after the operation. There were no significant differences in ATT and Lysholm scores between the operated groups. The IKDC score was lower in the ST-G group than in the ST group—9.57 (CI 14.89–4.25) (p < 0.001). No significant differences between injured and uninjured knees were detected in hamstring to quadriceps ratio strength and quadriceps limb symmetry index of the two operated groups, but the hamstring limb symmetry index was significantly lower in the ST-G group than in the ST and control groups. This study shows that using an ST-G autograft for ACLR yielded less flexor strength and worse results in some patient-reported outcome measures (PROM) than using an ST autograft five years after the operation. The observed results let us suggest that the use of one autograft hamstring tendon for ACLR is clinically preferable to the use of two hamstring tendons.

Rate of Torque Development in the Quadriceps after Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autografts in Young Female Athletes.

This study aims to compare the limb symmetry index (LSI) of the rate of torque development (RTD) of the quadriceps with that of the peak torque after anterior cruciate ligament reconstruction (ACLR) using semitendinosus and gracilis tendon (STG) autografts and to investigate the associations of the LSI of torque parameters with patient-reported knee function. The participants included 23 female athletes after ACLR with STG grafts. Isometric quadriceps tests were performed using an isokinetic dynamometer. The peak torque, RTD100 (0 to 100 ms) and RTD200 (100 to 200 ms) were determined using torque-time curves. Comparisons of the LSI of torque parameters was performed by ANOVA. Univariate regression analysis was used to examine the relationship between the LSI of torque parameters and the patient-reported knee function. The LSIs of the peak torque and RTD200 were significantly lower than that of the RTD100 (p = 0.049, p = 0.039, respectively). Regression analysis showed that the LSI of the peak torque was associated with the patient-reported knee function (R2 = 0.40, p = 0.001). It would be useful to evaluate the peak torque in young female athletes under the age of 18 and at 8–10 months after ACLR with STG grafts.

Multiplanar knee kinematics-based test battery helpfully guide return-to-sports decision-making after anterior cruciate ligament reconstruction.

Background: There are currently no well-established criteria to guide return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). In this study, a new test battery consisting of subjective and objective tests, especially multiplanar knee kinematics assessment, was developed to aid RTS decision making after ACLR. Methods: This study was conducted with 30 patients who were assessed a mean of 9.2 ± 0.5 months after ACLR. All patients underwent complete evaluations of both lower limbs with four objective assessments [isokinetic, hop, knee laxity, and 6–degree of freedom (6DOF, angle: flexion-extension, varus-valgus, internal-external rotation; translation: anteroposterior, proximodistal, mediolateral) knee kinematics tests] and two subjective assessments [International Knee Documentation Committee (IKDC) and Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) questionnaires]. Limb symmetry indices (LSIs) of knee strength, hop distance, and range of motion (ROM) of knee kinematics were calculated. LSI ≥90%, IKDC scale score within the 15th percentile for healthy adults, and ACL-RSI score >56 were defined as RTS criteria. Results: Significant differences between affected and contralateral knees were observed in the quadriceps strength (p < 0.001), hamstring strength (p = 0.001), single hop distance (p < 0.001), triple hop distance (p < 0.001), and rotational ROM (p = 0.01). Only four patients fulfilled the overall RTS criteria. The percentages of patients fulfilling individual criteria were: quadriceps strength, 40%; hamstring strength, 40%; single hop distance, 30%; triple hop distance, 36.7%; knee ligament laxity, 80%; flexion-extension, 23.3%; varus-valgus rotation, 20%; internal-external rotation, 66.7%; anteroposterior translation, 20%; proximodistal translation, 33.3%; mediolateral translation, 26.7%; IKDC scale score, 53.3%; and ACL-RSI score, 33.3%. Conclusion: At an average of 9 months after ACLR, objectively and subjectively measured knee functional performance was generally unsatisfactory especially the recovery of knee kinematics, which is an important prerequisite for RTS.

Low percentage of patients passed the ‘Back in Action’ test battery 9 months after bone-patellar tendon-bone anterior cruciate ligament reconstruction

BackgroundAnterior cruciate ligament (ACL) reconstruction is recommended in patients who intend to return to high-level sports. However, there is only a 55–80% return to pre-injury level of sports after ACL reconstruction, with a re-injury rate up to 20%. The aim of this study was to determine the percentage of patients passing the Back in Action (BIA) test 9 months after primary bone-patellar-tendon-bone (BPTB) ACL reconstruction, and evaluate the association between passing the BIA test and patient reported outcome measurements (PROMs). MethodsPatients underwent the BIA test 9 months after BPTB ACL reconstruction. In total 103 patients were included. Passing the BIA test (PASSED-group) was defined as a normal or higher score at all sub-tests with limb symmetry index (LSI) ≥90% for the dominant leg and LSI >80% for the non-dominant leg. Patients who did not meet these criteria were defined as the FAILED-group. PROMs included the International Knee Documentation Committee, Knee injury Osteoarthritis Outcome Score and Anterior Cruciate Ligament-Return to Sport after Injury. ResultsEighteen patients (17.5%) passed the BIA test 9 months after BPTB ACL reconstruction. PROMs were not statistically significant different between the PASSED- and FAILED-group. ConclusionLow percentage of patients passed the BIA test 9 months after BPTB ACL reconstruction. Although current PROMs cut-off values were met, the BIA test results show persistent functional deficits. Therefore, the BIA test could be of additional value in the decision-making process regarding return to sport (RTS). This study highlights the need for additional rehabilitation as RTS in a condition of incomplete recovery may increase the risk of re-injury. Level of evidenceII.

A Comparison of Electromyographic Inter-Limb Asymmetry During a Standard Versus a Sling Shot Assisted Bench Press Exercise.

The objective of this study was to compare peak surface electromyography (sEMG) activity of selected muscles along with inter-limb asymmetries between a control (CONT) and a Sling shot assisted (SS) bench press exercise. Ten resistance-trained males with at least three-year experience in resistance training (22.2 ± 1.9 years, 88.7 ± 11.2 kg, 179.5 ± 4.1 cm, bench press one-repetition maximum (1RM) = 127.3 ± 25.9 kg) performed the flat bench press exercise under two conditions at selected loads (85% and 100% of 1RM assessed without the SS). Peak sEMG amplitude of triceps brachii, pectoralis major, and anterior deltoid was recorded for the dominant and the non-dominant side of the body during each attempt. The comparison between the dominant and the non-dominant side was carried out using the limb symmetry index (LSI(%) = (2*(XR - XL)/(XR + XL))*100%) where XR = values of the right side and XL = values of the left side. There was a main effect of condition (p = 0.004; η2 = 0.64) and the load (p = 0.004; η2 = 0.63) for the triceps brachii LSI in parallel with a main effect of condition (p = 0.003; η2 = 0.42) for the anterior deltoid LSI. Post hoc analysis for the main effect of condition showed significant differences in the LSI between the CONT and SS conditions for the triceps brachii (p = 0.003; 1.10% vs. -8.78%) as well as for the anterior deltoid muscles (p = 0.03; 12.91% vs. 9.23%). The results indicate that the assistance of the Sling shot significantly affects the sEMG activity pattern on both the dominant and non-dominant sides of the body while influencing inter-limb asymmetries.

Muscle Strength And Loading Patterns During Sport-related Tasks In Persons With Acetabular Dysplasia

PURPOSE: Acetabular dysplasia (AD) is described as insufficient bony coverage of the femoral head by the acetabulum that leads to joint instability, pain, and decreased function. Little is known regarding the effects of AD on muscle strength and loading patterns during sport-related tasks. We compared muscle strength and loading patterns during squat and countermovement jump (CMJ) tasks between limbs and examined associations among these variables in persons with AD. METHOD: We enrolled 12 persons with AD (11 females) and evaluated isometric strength of the knee flexors and extensors and the hip flexors, extensors, and abductors using an electromechanical dynamometer (Biodex 3). We used peak torque values (Nm/kg) for the involved and uninvolved limbs to calculate limb symmetry indices (LSI) for each muscle group. Loading patterns during a squat and CMJ takeoff and landing were evaluated using two portable force plates (ForceDecks). Average peak ground-reaction force (GRF) for the involved and uninvolved limbs (N/N) and LSI for each task were calculated. We used Wilcoxon signed-rank test to evaluate differences in muscle strength and loading patterns between limbs. We examined associations between involved limb muscle strength and loading patterns using Spearman’s rho test. RESULT: The involved limb exhibited lower knee extensor strength compared to the uninvolved limb (involved = 1.75 Nm/Kg; uninvolved = 2.11 Nm/Kg; p = 0.005). There were no other differences between limbs for the remaining muscle strength variables or for squat and CMJ loading patterns variables (all p > 0.05). Per muscle group, the following proportions exhibited ≥90% LSI: 41.7% for knee extensors and flexors and hip flexors; 66.7% for hip extensors; 90% for hip abductors. Per movement task, the following proportions exhibited ≥90% LSI: 72.7% for the squat; 90% for CMJ takeoff; 54.5% for CMJ landing. Higher hip extensor strength was associated with higher GRF during CMJ landing for involved limb (r = 0.70; p = 0.016). CONCLUSION: Persons with AD exhibited decreased involved limb knee extensor strength and asymmetric strength and loading patterns. Higher hip strength was associated with higher involved limb landing during CMJ. Further study of the associations among strength and joint loading patterns is needed in larger samples of persons with AD.

Knee Extensor Rate Of Torque Development Assessment Post-acl Reconstruction: Does Sampling Rate Matter?

Impaired quadriceps neuromuscular function is a hallmark of anterior cruciate ligament injury and reconstruction (ACLR). Recent investigations suggest that reduced knee extensor rate of torque development (RTD) is strongly associated with abnormal movement mechanics post-ACLR and persists at or beyond return to sport. RTD is typically quantified at high (≥1000 Hz) sampling rates (SR), which is a barrier to clinical assessment as most clinical equipment features low SR (100 Hz). PURPOSE: To determine how SR influences knee extensor RTD in collegiate athletes near return to sport post-ACLR. METHODS: 35 Division I athletes (age 20.6 ± 1.6 y, BMI 25.0 ± 3.3 kg/m2, 21 female) performed rapid maximal effort isometric knee extension contractions at 9.1 ± 2.5 months post-ACLR on an isokinetic dynamometer. Torque signals were sampled at 2000 Hz. RTD was characterized with multiple variables: from contraction onset to 50, 100, and 200 ms (RTD0-50, RTD0-100, and RTD0-200, respectively), in sequence from 50 to 100 ms and 100 to 200 ms (RTD50-100 and RTD100-200), as the slope of 20-80% of peak torque (RTD20-80), and as the maximal instantaneous slope (RTDPeak). Torque signals were then downsampled to 100 Hz and all RTD variables re-calculated. Limb Symmetry Indices (LSI) were computed for all variables at both SR. Bland-Altman analyses, intraclass correlation coefficients (ICC), and root-mean-square errors (RMSE) assessed the agreement between 2000 Hz and 100 Hz RTD variables for both involved limb RTD and between-limb LSIs. RESULTS: Knee extensor RTD0-50, RTD50-100, and RTD0-100 demonstrated the lowest levels of agreement between 100 Hz and 2000 Hz SR. Conversely, RTD0-200, RTD20-80, and RTDPeak had the highest levels of agreement.CONCLUSIONS: Involved limb RTD and RTD LSI for RTD0-200, RTD20-80, and RTDPeak can be accurately assessed with reduced sampling rates, thereby facilitating use of clinically available equipment for assessing knee extensor RTD post-ACLR.

Identification and Predictors of Age-Relevant and Activity-Relevant Hop Test Targets in Young Athletes After Anterior Cruciate Ligament Reconstruction.

Performance symmetry between limbs (limb symmetry index [LSI] ≥ 90%) on a battery of single-leg hop tests is recommended to inform return-to-sport (RTS) decisions after anterior cruciate ligament (ACL) reconstruction (ACLR). Achieving current hop test symmetry values has not been associated with future clinical outcomes. The identification of age-relevant and activity-relevant target values to benchmark the hop test performance of young athletes post-ACLR may provide greater specificity and clinical relevance for interpretation of hop test data. To identify single-leg hop test-target values for individual-limb performance and symmetry between limbs for athletes without a history of ACL injury and evaluate the proportion of young athletes post-ACLR who met the newly derived target values at the time of RTS clearance. The secondary objective was to test the hypothesis that better function and strength would be associated with achieving the newly derived hop test target values. Cross-sectional study. Pediatric medical center and academic medical center. A total of 159 young athletes (age = 16.9 ± 2.2 years) at the time of RTS clearance after primary, unilateral ACLR and 47 uninjured control athletes (age = 17.0 ± 2.3 years). All participants completed a single-leg hop test battery (single hop, triple hop, and crossover hop for distance [cm], and 6-m timed hop [seconds]). Raw distance values were normalized by body height, and LSI (%) was calculated for each hop test. Target values were defined as the lower bound of the 95% CI for each hop test, using control group data. Participants with ACLR also completed the Knee injury and Osteoarthritis Outcome Score subscales and a quadriceps femoris strength (newton meters/kilogram) assessment. Logistic regression determined predictors of achieving hop test target values in the ACLR group among injury, function, and strength data (P < .05). In the ACLR group, 79% to 84% of participants met the 90% LSI threshold on each hop test. They achieved the target values for surgical-limb performance in the following proportions (% participants): single hop = 29%, triple hop = 24%, crossover hop = 30%, 6-m timed hop = 18%, all hops= 12%. Also, they met the target values for LSI in the following proportions: single hop = 43%, triple hop = 48%, crossover hop = 50%, 6-m timed hop = 69%, all hops = 25%. The only predictor of achieving all hop test targets for surgical-limb performance was greater surgical-limb quadriceps femoris strength (odds ratio = 4.10, P = .007). We noted a trend toward quadriceps femoris strength LSI ≥ 90% (odds ratio = 2.44, P = .058) as a predictor for meeting all hop test symmetry targets. At the time of RTS post-ACLR, only a small proportion of young athletes achieved the age-relevant and activity-relevant single-leg hop test targets for surgical-limb performance or symmetry between limbs, even though a majority met the traditionally recommended 90% LSI threshold on hop tests.

Why More Is Better: Integrating Sports Rehabilitation With Group-based Strength &amp; Conditioning After ACL Reconstruction

Current return to sport (RTS) timelines after anterior cruciate ligament reconstruction (ACLR) suggest a minimum of 9 months before returning to competitive sports. Time, quadriceps limb symmetry index (qLSI) deficits and movement mechanics are recognized as indicators of RTS surgical limb performance and re-injury risk reduction. Current isolated therapy models may not provide appropriate skilled rehabilitation leaving individuals with impairments near the end of their care. PURPOSETo examine the effects of combined therapy and group-based strength training on known RTS strength criteria following ACLR surgery. METHODSTwenty-two individuals (17 +/- 2 years) having undergone ACLR (CON) were age, sex and graft harvest matched with individuals who participated in a group-based strength and conditioning program between 3 and 9 months post-surgery (ACLRSC). 900 flexion isometric dynamometer strength testing was administered at 3, 6 & 9 months post-surgery. Individuals maximally kicked out for five seconds and was repeated 3 times. Dependent strength variables were average peak torque (Nm), relative torque (Nm/kg) and qLSI (%). ACLRSC completed strength sessions between 3 and 9 month testing (40 +/- 1 visits). The primary quadriceps specific stimulus was closed kinetic chain, semi supported, single leg squat exercises beginning with an asymmetrical loading ratio of 3:1 of exercise sets and progressed to 2:1 and 3:2 for the surgical limb compared to nonsurgical. Independent samples t-tests were used to determine differences in strength variables per group. RESULTSNo significant differences between groups at all time points in surgical limb average peak torque or relative torque (p > .05) was. No difference was found in qLSI at 3 or 6 (p > .05) months. However, at 9 months post-surgery qLSI was significantly higher in the ACLRSC group compared to CON (p = 0.03). CONCLUSIONIndividuals who completed combined therapy and training during rehabilitation reach RTS qLSI criteria at 9 months post-surgery compared to those who do not complete additional training. This model of combined therapy and group-based strength training proves to increase positive functional outcomes after ACLR. It further justifies the importance of a team based, patient centered, objective measure driven rehabilitation model.

Patient Reported Outcomes Among Patients With Disagreeing Pass Rates Among Performance Tests In Patients With ACLR

Purpose: Performance test batteries are often used to make return to activity decisions following ACL reconstruction (ACLR). Muscle strength symmetry, jumping symmetry and patient reported outcomes (PRO) are used by clinicians to assess outcomes based on pre-defined thresholds that may be an indicator of recovery. The purpose of this study was to compare PRO in patients with disagreeing outcomes among strength and jumping tests after ACLR. Methods: A total of 289 participants with primary unilateral ACLR (22.6 ± 9.47 yr, 140 M, 172.1 ± 10.4 cm, 75.8 ± 18.0 kg, 6.8 ± 1.5 months post ACLR) completed a test battery of isokinetic knee extension at 90°/s, single leg hop test for distance, and 2 PRO measures (IKDC and KOOS). Peak torque during knee extension and maximum jump distance during a single leg hop were used to calculate limb symmetry index (LSI = (ACLR / contralateral side)/100). We operationally defined “pass” as LSI ≥ 90% for each test. Patients were stratified by agreement in passing strength and jump tests: 1 = Pass Both Tests, 2 = Pass Strength Test Only, 3 = Pass Jump Test Only, and 4 = Fail both tests. We compared IKDC and KOOS knee related quality of life (QOL) scores among the groups using a one-way ANOVA and post hoc contrasts where appropriate. Alpha level was set at α <0.05. Results: We observed group main effects for IKDC (F(3,285) = 12.9, p < 0.001) and KOOS QOL (F(3,285) = 5.6, p = 0.001) scores. Post hoc contrasts revealed that groups 1 (86.8 ± 8.7) and 3 (84.8 ± 11.6) reported higher IKDC than 4 (76.0 ± 13.4, p < 0.001). Groups 1 (74.3 ± 13.66) and 3 (71.5 ± 19.1) reported higher KOOS QOL scores than 4 (62.4 ± 21.5, p = 0.03 & p = 0.002 respectively). Conclusion: Patients with ACLR who passed both tests had highest PRO values while those who failed both tests had the lowest. Disagreement in passing strength and jump components of test batteries influences perceived knee function and quality of life. The relationship seems to be primarily driven by passing jump test despite failing strength tests.

Explosive hamstrings strength asymmetry persists despite maximal hamstring strength recovery following anterior cruciate ligament reconstruction using hamstring tendon autografts

PurposeTo investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and to determine the interaction of time and sex on maximal and explosive strength symmetry.MethodsA total of 38 female and 51 male participants were assessed during early (3–6 months post-operative) and late (7–12 months post-operative) phases of rehabilitation following ACLR. Maximal (concentric and isometric peak torque) and explosive (isometric RTD) hamstring and quadriceps strength were assessed and presented as limb symmetry index (LSI).ResultsMaximal concentric hamstrings asymmetry (Early: 86 ± 14; Late 92 ± 13; p = 0.005) as well as maximal concentric (Early, 73 ± 15; Late 91 ± 12; p < 0.001) and explosive (Early: 82 ± 30; Late: 92 ± 25; p = 0.03) quadriceps asymmetry decreased from early to late rehabilitation. However, there were no significant changes in maximal isometric quadriceps strength and explosive isometric hamstring strength in the same time period. Females had a larger asymmetry in maximal concentric (Females: 75 ± 17; Males: 81 ± 15; p = 0.001) and explosive (Females: 81 ± 32; Males: 89 ± 25; p = 0.01) quadriceps strength than males throughout rehabilitation. There were no sex differences in maximal and explosive hamstring strength. There were no sex by time interactions for any variables.ConclusionExplosive hamstring strength asymmetry did not improve despite recovery of maximal hamstring strength during rehabilitation following ACLR with HT autografts. While sex did not influence strength recovery, females had larger maximal and explosive quadriceps strength asymmetry compared to males throughout rehabilitation following ACLR.Level of evidenceLevel III

There Is Substantial Variation in Rehabilitation Protocols Following Anterior Cruciate Ligament Reconstruction: A Survey of 46 American Orthopaedic Surgeons

To identify the clinical practice preferences of orthopaedic surgeons regarding anterior cruciate ligament reconstruction (ACLR) rehabilitation through a survey of members of the Arthroscopy Association of North American (AANA) and the American Orthopaedic Society for Sports Medicine (AOSSM). An online survey was distributed to members of AANA and AOSSM between November 2020 and September 2021. Participants reported on their clinical preferences for ACLR protocol development and patient selection, use of technology in ACLR recovery and rehabilitation, and preferences for advancing through multiple phases of the rehabilitative process. Responses from 46 orthopaedic surgeons were analyzed. Patient-reported outcome measures were not found to be utilized often at various phases of the perioperative period. Thirty-eight (82.6%) participants reported utilization of postoperative bracing. There was no consensus on when participants allow their patients to advance through rehabilitation, but most report waiting 3 to 4 months for advancement to jogging/lateral movement, 6 to 8 months for return to noncontact sport, and 9 months of more for return to unrestricted sport. Many participants utilize functional and strength testing with associated limb symmetry indices to determine patient readiness to return to sport, with 18, 26, and 25 participants reporting use of functional testing and 28, 26, and 27 participants reporting use of strength testing at the return to jogging/lateral movements, noncontact return to sport, and unrestricted return-to-sport phases, respectively. This study provides an insight into the rehabilitative protocols and modalities utilized for ACLR by orthopaedic surgeons in practice across the United States. There is notably substantial variation in rehabilitative patterns and preferences, particularly with regards to what constitutes criteria for progressing patients through the phases of returning to unrestricted sport. Additionally, our findings show that while many surgeons believe that quantitative assessment technology could be beneficial in decision-making for returning patients to sport, there are still many barriers that stand in the way of its implementation into clinical practice. Postoperative rehabilitative protocols after ACLR vary by surgeon.

Deficits in Contralateral Limb Strength Can Overestimate Limb Symmetry Index After Anterior Cruciate Ligament Reconstruction

PurposeTo evaluate whether contralateral limb strength represents a dynamic, rather than static, data point after anterior cruciate ligament reconstruction (ACL-R).MethodsPatients who underwent isolated ACL-R at a single institution were identified. Patients completed an institutional Lower-Extremity Assessment Protocol (LEAP) testing protocol at 6 and 9 months postoperatively. Extension strength and flexion strength of the ipsilateral and contralateral limbs and limb symmetry index (LSI) were compared between the 6- and 9-month testing outcomes. Subgroup analysis compared patients demonstrating less than or greater than 10% change in contralateral limb flexion and extension strength between 6 and 9 months postoperatively.ResultsA total of 144 subjects were included in this study. On average, contralateral limb flexion and extension strength increased 2-4% between 6 and 9 months postoperatively. However, the contralateral limb increased >10% from 6 to 9 months in extension and flexion strength in 35/144 (24.3%) and 55/144 (38.2%) of patients, respectively. The cohort with >10% change between 6 and 9 months had significantly weaker contralateral extension and flexion strength at 6 months compared to the cohort that demonstrated <10% change (extension: 2.00 vs 2.39; P < .001; flexion: 0.84 vs 1.08; P < .001), but similar ipsilateral limb performance. Therefore, the >10% change cohort had a significantly greater LSI at 6 months compared to the <10% change cohort (67.3% vs 59.4%; P = .006). No demographic or operative factors correlated with which patients demonstrated >10% flexion or extension strength changes of the contralateral limb.ConclusionA large percentage of patients demonstrate significant changes in their contralateral limb flexion and extension strength between 6 and 9 months postoperatively that result from an initial contralateral limb strength deficit. This may limit the utility of the contralateral limb as a control for comparison to the operative extremity during return to sport assessment.

Isolated radial tears of the lateral meniscus midbody: a case series of professional athletes treated with outside-in repair.

The main aim of the study is to assess clinical and functional outcomes of arthroscopic outside-in repair of isolated radial tears of the midbody of lateral meniscus in professional athletes and to evaluate the return to the sport activity after surgery. A retrospective data collection on professional athletes with isolated complete lesion of the midbody of lateral meniscus, treated with arthroscopic outside-in repair was carried out. Outcome measures included functional assessment, Limb Symmetry Index (LSI) and Hamstring Quadriceps Ratio (HQR) and Lysholm score collected before surgery and at 4-month follow-up. Data on return to sport practice and re-injury were also retrieved. Fourteen patients satisfied the selection criteria. Full return to professional sport activity (Tegner 10) was registered in the 86% of the cohort at 4months after the surgery. Functional testing of the athletes showed a return of the LSI and HQR to the pre-surgical condition, demonstrating a full recovery of the functional ability and muscle strength. Similarly, clinical evaluation through Lysholm score showed an improvement, reaching an average of 97.7 points at 4months follow-up. A good functional recovery and a high rate of return to play has been observed in a population of professional athletes, at 4months after outside-in repair.

Reactive strength index during single-limb vertical continuous jumps after anterior cruciate ligament reconstruction: cross-sectional study

BackgroundThe association of the reactive strength index (RSI) during single-limb vertical continuous jumps (SVCJs) with single-limb hop tests in athletes after anterior cruciate ligament reconstruction (ACLR) is unclear. Thus, this study aimed to confirm the measurement properties of the RSI during SVCJs in athletes with ACLR at the phase of determining the timing of their return to sport.MethodsRSI during SVCJs and single-limb hop (single, triple, and crossover) tests were measured for post-ACLR and healthy athletes. The limb symmetry index (LSI) was calculated using the measurements of each parameter. For each test, patients were divided into two subgroups according to their LSI score (≥ 90%, satisfactory; < 90%, unsatisfactory). Fisher’s exact test was used to examine the association of single-limb hop tests with RSI during the SVCJs.ResultsA total of 21 post-ACLR and 17 healthy athletes completed all the tests. RSI during SVCJs was significantly lower on the involved limb than on the uninvolved limb in post-ACLR athletes (P < 0.001). The LSI of RSI during SVCJs of post-ACLR athletes was significantly lower than that of the healthy athletes (P < 0.01). Among the post-ACLR athletes, < 30% of those with LSIs > 90% in the single-limb hop tests had an LSI > 90% of the RSI during SVCJs.ConclusionsRSI during SVCJs of post-ACLR athletes was significantly lower on the involved limb than on the uninvolved limb, and the asymmetry was more remarkable in the SVCJs than in the single-limb hop tests.