Single-leg Hop For Distance Research Articles

Neurocognitive demands reducejump distance and coordination variability of the injured leg in athletes after anterior cruciate ligament reconstruction.

The study aimed to evaluate the impact of neurocognitive reliance on jump distance and lower extremity kinematics in individuals who had undergone anterior cruciate ligament reconstruction (ACLR). This was achieved by comparing hop performance under standard and neurocognitive conditions. Thirty-two patients after ACLR and 32 healthy controls (CTRL) participated. Both groups performed a single-leg hop for distance (SLHD) and two neurocognitive hop tests, each designed to evaluate distinct aspects of neurocognition. The neurocognitive tests included the reaction SLHD (R-SLHD), measuring reaction to a central stimulusand working memory SLHD (WM-SLHD) assessing response to a memorized stimulus amidst distractor stimuli. Distances were assessed for the three-hop tests. In addition, joint kinematics were collected to calculate lower extremity coordination of the lower extremity. SLHD performance was defined as the mean hop distance per condition per leg for each participant and was analyzed using a mixed ANOVA with condition and leg as the within-subjects factors and the group (ACLR or CTRL) as the between-subjects factor. Differences in joint coordination variability were analyzed using two-sample t-test statistical parametric mapping (SPM) with linear regression. The WM-SLHD resulted in a significantly decreased jump distance compared with the standard hop test both for ACLR and CTRL. Furthermore, the leg difference within the ACLR group increased under higher cognitive load as tested with the WM-SLHD, indicating leg-specific adaptations in lower extremity coordination. Neurocognitive single-leg hop tests resulted in reduced jump distance in CTRL and ACLR. The neurocognitive hop test revealed changes in coordination variability for the CTRL and the uninjured leg of ACLR individuals, whereas the injured leg's coordination variability remained unaltered, suggesting persistent cognitive control of movements post-ACLR. Level III.

The effect of post-match fatigue on physical performance in adolescent soccer players.

Soccer involves many physically challenging actions and engaging in such activities can induce a decline in performance due to physical fatigue which predisposes players to develop injuries. The present study aimed to examine the impact of post-match fatigue on functional performance and Inter-Limb Asymmetry Index (LSI) in adolescent soccer players. Thirty-eight adolescent male soccer players (15-18 years) completed a battery of functional performance measures (Rate of Perceived Exertion (RPE) scale, 10 m sprint, agility T-test, and Single leg hop for distance (SLHD) test). The data collection started prior to a soccer match and consisted of two testing sessions; two hours before the match, while the subsequent testing session was performed within two hours immediately following the match. The study results revealed a significant effect of post-match fatigue on change of direction abilities and SLHD (moderate effect size). However, no significant differences were observed in the 10 m sprint test and LSI (P>0.05). Functional performance measures such as agility test and SLHD test can detect physical ability changes due to post-match fatigue in adolescent soccer players. The study findings offer insightful and practical information on the importance of employing field-based functional performance measures in monitoring players' recovery following a game.

Poster 321: Predictive Value of Functional Assessments During Perioperative Rehabilitation in Anterior Cruciate Ligament Reconstruction (ACLR)

Objectives: Perioperative rehabilitation is critical to restoring function and preventing reinjury in ACLR patients. Single-leg hop and isokinetic strength testing are commonly utilized by clinicians to assess patient progress. The impact of early stage progress on later stage outcomes is, however, not well understood. This study aimed to identify the effects of early postoperative isokinetic quadriceps strength and single-leg hop performance on functional recovery after primary ACLR, to determine the manner in which changes in these parameters during perioperative rehabilitation relate to fast and successful functional recovery. Methods: Patients having a primary ACLR were consented into a long-term study and were retrospectively reviewed with the following inclusion criteria: ACLR using a contralateral patellar tendon graft with normal extension ROM and stability at 2 months postoperative, per the International Knee Documentation Committee (IKDC) objective form. Patients were excluded with a preoperative modified Tegner level <7. Predictor variables included 180°/second isokinetic quadriceps strength test (preoperative, 2 months, 4 months) and single leg hop for distance (preoperative and 4 months). Strength was assessed using limb symmetry index (LSI) with the ACLR knee strength being divided by the graft donor knee strength, percent of preoperative normal, and percent change over time at each interval, while hop testing was normalized to height. Outcome variables assessed were return to sport (RTS) time in months, return to preoperative modified Tegner level in the first 12 months after surgery (yes/no), and Cincinnati Knee Rating System (CKRS) at 12 months postoperative. Stepwise multiple regression analysis was used to predict RTS time, return to preoperative modified Tegner level, and CKRS based on demographics and objective measures. Results: A total of 1093 patients were eligible for analysis and 607 were used for the RTS model, 724 for the return to preinjury Tegner level model, and 705 for the CKRS model. Mean age for the cohort was 19.6 ± 5.5 years (range, 11.9-39.7) and 52.1% were male. In the model predicting RTS time, the following variables reduced RTS time: female sex, younger age, higher preoperative LSI, higher ACLR knee strength gains from preoperative to 2 month, and higher normalized single leg hop distance. In the model predicting a return to preoperative Tegner level, the following variables increased the likelihood: younger age, lower preoperative Tegner level, lower strength deficits with LSI at 2 months, and higher normalized single leg hop distance. In the model predicting CKRS scores, the following variables increased the score: younger age and higher normalized single leg hop distance. Model statistics can be seen in Table 1. Conclusions: The study found several early rehabilitation performance measures significantly influenced key outcomes. Perioperative rehabilitation should promote early relative gains in quadriceps strength for the ACLR knee, maintaining limb symmTaetry, and maximizing single leg hop distance to encourage faster RTS, higher subjective scores, and improve the likelihood of patients returning to preoperative activity levels. By quantifying the importance and predictiveness of these rehabilitation performance metrics, clinicians may improve their protocols to promote superior outcomes following ACLR.

Poster 342: Return to Sport Rates and Objective Measures after ACL Reconstruction for High Level Basketball Players

Objectives: Return to sports (RTS) decisions for high-level basketball players after an anterior cruciate ligament reconstruction (ACLR) are multifactorial. The literature focuses mainly on sports performance metrics and lacks objective rehabilitation measures. The purpose of this study was to determine objective measure differences following an ACLR between basketball players competing at the college/professional, high school, and recreational levels. Our hypothesis was that basketball players competing at the college/professional level would have superior performance with objective measures following an ACLR, compared to those competing at the high school and recreational levels. Methods: Patients were retrospectively selected based on the following inclusion criteria: ACLR with a contralateral patellar tendon graft (PTG), preoperative activity level of ≥8 on the modified Tegner activity rating scale, ≤25 years old, and reported playing basketball. Exclusions included: revisions, bilateral procedures, or were missing data needed for analysis. Patients were split based on their preoperative activity level (level 8 = recreational, level 9 = high school, level 10 = college/professional). Each patient received a mini open, contralateral PTG utilizing the same surgical methods and followed the same accelerated rehabilitation approach. Postoperative outcome measures included the difference in extension range of motion (ROM) at 2 weeks, difference in flexion ROM at 3 months, percent deficit in isokinetic quadriceps strength and single leg hop for distance at 4 months, and the manual maximum difference on the KT arthrometer at 2 months. Statistical analysis included chi-square and analysis of variance where appropriate. Results: Of the 329 patients, 69 were level 8, 224 were level 9, and 36 were level 10 with mean ages of 19.6, 16.4, and 19.1 years, respectively. The percent of males differed by group with level 8 at 78.3%, level 9 at 29.5%, and level 10 at 27.8% (p < 0.001). The overall rate of return to competitive basketball for the cohort was 96.0%. The rate of return to competitive basketball was not statistically significantly different among the groups with level 10 having the highest rate (97.2%), followed by level 9 (96.4%) and then level 8 (94.2%), p = 0.659. Level 10 athletes had the lowest strength deficit with a mean of 9.3%, compared to 12.5% for level 9, and 15.6% for level 8, p=0.017. Single leg hop deficit was also different among groups with level 10 at 6.9%, level 9 at 6.2%, and level 8 at 10.4%, p < 0.001. Knee ROM and stability were not statistically different among the groups. Conclusions: The rate of return to competitive basketball is the same among all high-level basketball players. Objectively, level 10 athletes had superior strength and single leg hop performance compared to recreational basketball players. Although the return to competitive basketball rate is the same among all groups, recreational basketball players tend to be weaker than college/professional players, therefore, added emphasis on this aspect of their rehabilitation would be beneficial for this population.

Residual deficits of knee and hip joint coordination and clinical performance after return to sports in athletes with anterior cruciate ligament reconstruction

BackgroundBiomechanical changes and neuromuscular adaptations have been suggested as risk factors of secondary injury in individuals after anterior cruciate ligament reconstruction (ACLr). To achieve a better understanding of preventive mechanisms, movement quality is an important factor of consideration. Few studies have explored time-series analysis during landing alongside clinical performance in injured and non-injured individuals. The purpose of the study was to investigate the biomechanical risks of recurrent injury by comparing clinical and jump-landing performance assessments between athletes with ACLr and healthy controls.MethodThis study was observational study. Sixteen athletes with and without ACLr voluntarily participated in clinical and laboratory measurements. Single-leg hop distance, isokinetic tests, landing error score, and limb symmetry index (LSI) were included in clinical report. Lower limb movements were recorded to measure joint biomechanics during multi-directional landings in motion analysis laboratory. Hip-knee angle and angular velocity were explored using discrete time-point analysis, and a two-way mixed analysis of variance (2 × 4, group × jump-landing direction) was used for statistical analysis. Time series and hip-knee coordination analyses were performed using statistical parametric mapping and descriptive techniques.ResultsSignificantly lower single-leg hop distance was noted in ACLr group (158.10 cm) compared to control group (178.38 cm). Although the hip and knee moments showed significant differences between four directions (p < 0.01), no group effect was observed (p > 0.05). Statistical parametric mapping showed significant differences (p ≤ 0.05) between groups for hip abduction and coordinate plot of hip and knee joints. Athletes with ACLr demonstrated a higher velocity of hip adduction. Time-series analysis revealed differences in coordination between groups for frontal hip and knee motion.ConclusionsAthletes with ACLr landed with poor hip adduction control and stiffer knee on the involved side. Multi-directions landing should be considered over the entire time series, which may facilitate improved movement quality and return to sports in athletes with ACLr.

Single Leg Hop Performance After Anterior Cruciate Ligament Reconstruction: Ready for Landing but Cleared for Take-Off?

While the landing phases of the single-leg hop for distance (SLHD) are commonly assessed, limited work reflects how the take-off phase influences hop performance in patients with anterior cruciate ligament reconstruction (ACLR). To compare trunk and lower extremity biomechanics between individuals with ACLR and matched uninjured controls during take-off of the SLHD. Cross-sectional study design. Laboratory setting. 16 individuals with ACLR and 18 uninjured controls. Normalized quadriceps isokinetic torque, hop distance, and respective limb symmetry indices (LSI) were collected for each participant. Sagittal and frontal kinematics and kinetics of the trunk, hip, knee, and ankle, as well as vertical and horizontal ground reaction forces (GRF) were recorded for loading and propulsion of the take-off phase of the SLHD. Those with ACLR had weaker quadriceps peak torque in the involved limb (p=0.001) and greater strength asymmetry (p<0.001) compared to controls. Normalized hop distance was not statistically different between limbs or between groups (p>0.05) and hop distance symmetry was not different between groups (p>0.05). During loading, the involved limb demonstrated lesser knee flexion angles (p=0.030) and knee power (p=0.007) compared to the uninvolved limb, and lesser knee extension moments compared to the uninvolved limb (p=0.001) and controls (p=0.005). During propulsion, the involved limb demonstrated lesser knee extension moment (p=0.027), knee power (p=0.010), knee (p=0.032) and ankle work (p=0.032), anterior- posterior GRF (p=0.047), and greater knee (p=0.016) abduction excursions compared to the uninvolved limb. Between-limb differences in SLHD take-off suggest a knee underloading strategy in the involved limb. These results provide further evidence that distance covered during SLHD assessment can overestimate function and fail to identify compensatory biomechanical strategies.

Addition of anterolateral ligament reconstruction to primary anterior cruciate ligament reconstruction could benefit recovery of functional outcomes

This study aimed to compare functional outcomes sequentially up to 1 year after combined anterior cruciate ligament reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) and isolated ACLR. Fifty patients who underwent ACLR with versus without ALLR were analyzed at four different time points (preoperatively and 3, 6, and 12 months postoperatively). For the functional outcomes, muscle strength and acceleration time (AT) were measured using an isokinetic dynamometer. Proprioception was evaluated using joint position sense and dynamic postural stability. Patient-reported outcomes were measured using the Tampa Scale for Kinesiophobia (TSK-11) scores. Functional performance was assessed using single-leg hop distance (SLHD) and Limb Symmetry Index. In the operated knees, quadriceps (at 6 months postoperatively, p = 0.003) and hamstring (at 6 and 12 months postoperatively, p < 0.001) strength were significantly higher in the combined ACLR and ALLR group than the isolated ACLR group. The TSK-11 (at 6 and 12 months postoperatively, p < 0.001) was significantly lower in the combined ACLR and ALLR group than the isolated ACLR group. SLHD was significantly higher in the combined ACLR and ALLR group than the isolated ACLR group (at 6 months, p = 0.022 and at 12 months, p = 0.024). The addition of ALLR to primary ACLR yielded better muscle performance, fear of movement, and functional performance than isolated ACLR.

Evaluation of hop test movement quality to enhance return to sport testing. A cross-sectional study.

Return to Sport tests with functional hop tests are often used to decide when a person is ready to return to sport after an anterior cruciate ligament (ACL) injury. Poor movement quality, such as knee valgus, hip adduction and hip internal rotation is considered a risk factor for ACL injury. However, it is unclear whether existing tests adequately cover the aspect of movement quality. This study aims to investigate whether there is a relationship between the calculated limb symmetry index (LSI) of hop tests as an indication of performance and the total score of the "Quality First" assessment (movement quality). The second aim is to examine the reliability of the newly developed "Quality First" assessment for evaluating movement quality in hop tests. The cross-sectional study recruited 34 patients with an ACL reconstruction. The vertical hop, single-leg hop for distance, and side hop tests were performed and recorded. The video recordings were assessed using the "Quality First" assessment. The Spearman correlation coefficient was calculated using the LSI and the "Quality First" total score. Intraclass correlation coefficients (ICC) and standard error of measurements (SEM) were used to calculate intra- and interrater reliability. In addition, the minimal detectable change (MDC) was determined. The correlation test between the LSI and the "Quality First" total score showed no correlation for all three jumps (r = -0.1-0.02/p-value = 0.65-0.93). The interrater reliability of the "Quality First" assessment showed fair to good reliability (ICC2: 0.45-0.60), with SEM ranging from 1.46 to 1.73 and the MDC from 4.06 to 4.8. Intrarater reliability was good to excellent (ICC3: 0.73-0.85), with SEM values ranging from 0.89 to 1.09 and the MDC from 2.47 to 3.01. The quality of movement, measured with the "Quality First" assessment, indicated no correlation with the calculated LSI from jump performance, therefore movement quality should also be examined in Return to Sport tests. The "Quality First" assessment shows fair to good reliability when used by different raters. When used multiple times by the same rater, the assessment has good to excellent reliability.

Abnormal Lower Limb Biomechanics During a Bilateral Vertical Jump Despite the Symmetry in Single-Leg Vertical Hop Height in Athletes After ACL Reconstruction.

A limb symmetry index (LSI) of >90% for single-leg horizontal hop distance is recommended as a cutoff point for safe return to sports after anterior cruciate ligament reconstruction (ACLR). Despite achieving this threshold, abnormal lower limb biomechanics continue to persist in athletes after ACLR. Symmetry in single-leg vertical hop height appears to be more difficult to achieve and can be a better representation of knee function than single-leg horizontal hop distance. To explore whether an LSI of >90% for single-leg vertical hop height can represent normal lower limb biomechanics in athletes during a bilateral vertical jump after ACLR. Controlled laboratory study. According to the LSI for single-leg vertical hop height, 46 athletes who had undergone ACLR with an autologous ipsilateral bone-patellar tendon-bone or hamstring tendon graft were divided into a low symmetry group (LSI <90%; n = 23) and a high symmetry group (LSI >90%; n = 23), and 24 noninjured athletes were selected as the control group. The kinematic and kinetic characteristics during a bilateral vertical jump were compared between the low symmetry, high symmetry, and control groups. During the propulsion phase of the bilateral vertical jump, the operated side in the high symmetry group showed a lower knee extension moment than the nonoperated side (P = .001). At peak vertical ground-reaction force, the operated side in the high symmetry group showed a lower knee internal rotation moment compared with the control group (P = .016). Compared with the nonoperated side, the operated side in the high symmetry group showed a higher hip extension moment (P = .002), lower knee extension moment (P < .001), lower ankle plantarflexion moment (P < .001), and lower vertical ground-reaction force (P = .023). Despite achieving an LSI of >90% for single-leg vertical hop height, athletes after ACLR showed abnormal lower limb biomechanical characteristics during the bilateral vertical jump. Symmetrical single-leg vertical hop height may not signify ideal biomechanical or return-to-sports readiness in this population.

Restorative Physical Function and Patient-Reported Outcomes After Acute Lateral Ankle Sprain in High School Athletes.

Limited longitudinal data exist on patient-reported outcomes (PROs) after acute lateral ankle sprain (LAS). The impact of prospective hop testing on PROs at return to play (RTP) and 6 months post-RTP is unclear. To determine if high school athletes with an LAS who return to baseline physical function as measured by a single-leg hop for distance (SLHOP) have better PROs relative to individuals who return to symmetry. Cohort study. Ten high schools over 2 years. Two hundred six high school athletes who sustained an LAS were included. Baseline SLHOP testing was completed preinjury. Patient-reported outcomes were recorded at time of injury, RTP, and 6 months post-RTP. Participants were classified as symmetry (n = 134) or restorative (n = 72). Symmetry was defined as achieving an SLHOP performance within 10% of the uninjured limb at RTP. Restorative was defined as achieving an SLHOP performance within 10% of preinjury levels. The Foot and Ankle Ability Measure (FAAM)-Activities of Daily Living, FAAM-Sport, Patient-Reported Outcomes Measurement Information System (PROMIS) Anxiety, and PROMIS Depression were analyzed using a 2-way nonparametric analysis of variance. The interaction term of group by time was the main comparison of interest and was interpreted if significant. Post hoc multiple comparisons were performed using the Tukey-Kramer test. The restorative group reported better FAAM scores at RTP and 6 months post-RTP (P < .05) relative to the symmetry group. There were no differences in PROMIS Anxiety scores at time of injury, RTP, or 6 months post-RTP between groups (P > .05). There were no differences in PROMIS Depression scores at time of injury between groups (P = .34), but the restorative group had worse PROMIS Depression scores at RTP (P = .03). The restorative group reported better FAAM-ADL and FAAM-Sport scores at RTP and 6 months post-RTP relative to the symmetry group. Restoring individuals to baseline physical function rather than limb symmetry may ensure better PROs after an LAS.

Things to keep in mind when selecting physical assessments in youth soccer: Correlations between test performances, interlimb asymmetries, and effects of maturation.

A range of field-based tests have been proposed for inclusion in physical performance assessment batteries. However, there are obvious time and human resources constraints in applied settings. The knowledge of potential relationships between tests on performance, asymmetries, as well as maturation-induced changes, may help select the most informative and least time-consuming testing battery. The purposes of this study were: (1) to determine correlations in performance between different field-based tests, in interlimb asymmetry between those unilateral tests, and between asymmetry scores and test performances, and (2) to determine the influence of players' maturity status on test performances and asymmetries. A total of 309 male youth soccer players completed a nine-test battery including y-balance test, drop vertical jump, countermovement jump, single leg countermovement jump, standing long jump, single leg hop for distance, Illinois agility test, 10 m sprint, and 20 m sprint. The results revealed moderate-to-very large relationships between jump, sprint, and agility performances (r = 0.43-0.94), but weak-to-moderate correlations between these tests and balance scores (r ≤ 0.38). No relevant relationship (r ≤ 0.32) for asymmetries detected through different unilateral tests was found, nor between asymmetries and performance scores (r < 0.29). While maturity status clearly influenced players' performance, a limited impact on asymmetries was evident. Despite the mentioned relationships, the low shared variance between tests indicates that they should not be used interchangeably, and coaches should select those with the greatest specificity for the sport. Asymmetries do not influence performance, but their prevalence and unchanging nature with maturation can be seen as an opportunity for the identification of highly asymmetrical players and the application of interventions to improve the weaker limb, irrespective of the athlete's stage of development. To this end, the single leg countermovement jump might be viewed as an appropriate test in male youth soccer.

Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) subcategories are affected by subjective running ability and medial single-leg hop distance in postreconstruction patients at 6 months.

This study aimed to investigate the intricate relationship between physical function factors and each subcategory score of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale among patients following ACL reconstruction. Participants comprised 59 patients who had undergone primary ACL reconstruction using hamstring tendon. The ACL-RSI was completed 6 months after reconstruction and five physical functions were measured in patients on the same day. Simple linear regression was performed multiple times to investigate the relationship between ACL-RSI subcategory scores as a dependent variable and each independent variable (knee strength, leg anterior reach distance, single-leg hop [SLH] distances, side bridge endurance, and subjective running ability). Multiple regression analysis was performed using a stepwise method, with factors showing a risk rate <0.05 in simple linear regression analyses as independent variables and the ACL-RSI in each subcategory score as the dependent variable. Multiple regression analysis showed that subjective running ability affected all subcategories (p ≤ 0.001), and that the limb symmetry index of medial SLH distance affected both the Emotions (p = 0.047) and Confidence (p = 0.009) subcategories. Higher subjective running ability and greater limb symmetry in the medial SLH were thus positively associated with each dimension of psychological readiness. This study highlights the differential impact of physical function factors on specific subcategories of the ACL-RSI scale, providing clinicians with insights for designing targeted rehabilitation strategies. This original paper suggests the importance of analysing factors related to subcategory scores in addition to total ACL-RSI score, and could contribute to the understanding of determinants for a successful return to sport following ACL reconstruction. Level IV.

Association between single leg hop tests and patient reported outcome measures and patellar instability in patients with recurrent patellar dislocations

ObjectivesTo assess the associations between the single leg hop tests at two premises; baseline and the change after 12 months, and change in patient reported outcome measures and persistent instability...

Limb Symmetry Index of Single-Leg Vertical Jump vs. Single-Leg Hop for Distance After ACL Reconstruction: A Systematic Review and Meta-analysis.

The limb symmetry index (LSI) is recommended as a milestone of return to play (RTP), and relying on the LSI value of a single-leg hop for distance (SLHD) test may overestimate rehabilitation status. Identifying a more reliable functional test can help to carefully make decisions for RTP. The aim was to compare the LSI value of the SLHD test with that of a single-leg vertical jump (SLVJ) test after anterior cruciate ligament reconstruction (ACLR) and determine which test provides lower LSI values. The PubMed, Web of Science, Embase, and Cochrane Library databases were searched from inception to July 2022. Observational studies with participants who had both SLHD and SLVJ tests after ACLR and LSI values of an SLHD and SLVJ were included. Disagreements were resolved after discussion between the 2 researchers. Systematic review and meta-analysis. Level 4. Data on the primary outcomes (LSI values of the SLVJ and SLHD tests) were collected. Means and standard deviations (SDs) for each variable of interest were used to calculate standardized mean differences (SMDs). A total of 12 studies met the inclusion criteria for the meta-analysis. A total of 587 patients underwent SLHD and SLVJ tests at different time points after ACLR. Compared with the SLHD test, the SLVJ test provided lower LSI values (SMD -0.42; 95% confidence interval (CI) -0.67 to -0.17). Subgroup analysis found that the SLVJ test provided a lower LSI value than the SLHD test in a specific period (approximately 7-18 months after ACLR, SMD -0.53; 95% CI -0.91 to -0.14) and a similar LSI value at other times. The SLVJ test provided lower LSI values in a specific period (7-18 months after ACLR).

Knee function and quality of life in adolescent soccer players with Osgood Shlatter disease history: a preliminary study

The aim of the study was to assess psycho-physical deficits among young athletes with history of Osgood Shlatter Disease (OSD-H) compared to adolescents without history of knee pain (Control group). Eighteen participants were recruited from a group of 80 young (U14–U17) male soccer players. Medical records, and Knee Osteoarthritis Outcome Score (KOOS) were performed from both groups. The tests were conducted to assess the anthropometric characteristics, knee and ankle range of motion (Ely’s and Weight Bearing Lunge tests), and muscle power of the lower limbs (Leg Press, Single Leg Countermovement Jump, and Single Leg Hop for Distance). Results showed that overall patient-relevant outcomes following OSD (87%) were significantly lower than in the Control group (95%) (p < 0.05). Scores of the KOOS subscales revealed that Quality of Life and Function, Sports and recreational activities were significantly lower in the OSD-H group (p < 0.05). Although, there were no differences in subscale scores for Pain, Symptoms and Daily Activities. There were, also no difference between groups in range of motion angles and muscle power of the lower limbs values. The preliminary results support existing knowledge indicate that OSD may have a long-term influence on function, sports and recreational participation, and quality of life on young athletes.

Changes in Quadriceps Rate of Torque Development After Anterior Cruciate Ligament Reconstruction and Association to Single-Leg Hop Distance.

Quadriceps neuromuscular function is negatively affected after anterior cruciate ligament reconstruction (ACLR). The specific effect that the ACLR has on the quadriceps femoris rate of force production and its impact on functional recovery is unknown. The anterior cruciate ligament (ACL) limb would present persistent deficits in the rate of torque development (RTD), when compared with the non-ACL limb before ACLR until 9 months (9M) post-ACLR. Prospective cohort study. Level 3. Twenty-eight participants performed quadriceps maximum voluntary isometric contractions (MVICs) before (PRE), at 5 months (5M) and at 9M after ACLR. Single-leg hop distance was also assessed at 9M. Quadriceps RTD was calculated at 50, 100, and 200 ms after the onset of torque production. Maximum RTD was also calculated. A 2 (limb) × 3 (time) repeated-measures analysis of variance was used for RTD50, RTD100, RTD200, and RTDmax. Linear regressions were used to evaluate the associations of MVIC and RTD values at 5M and 9M with single-leg hop distance at 9M. The ACL limb had lower RTD values at all times compared with the non-ACL limb (P < 0.05). RTD of the ACL limb significantly decreased from PRE to 5M, and then recovered to PRE levels at 9M (P < 0.05). The non-ACL limb displayed no differences from baseline to either 5M or 9M. MVIC and RTD200 at 5M predicted (R2 = 0.313 and R2 = 0.262, respectively) single-leg hop distance at 9M, better than the strength and RTD at 9M (R2 = 0.235 and R2 = 0.128, respectively). Quadriceps RTD is negatively affected after ACLR, and deficits may persist at the time of return to activity. Strength and RTD during recovery at 5M may predict more than 25% of the variance in single-leg hop distance at 9M, independently; hence, both provide important information to monitor functional recovery post-ACLR. RTD should be measured to understand the changes in neuromuscular capacity after ACLR, and rehabilitation strategies that target quick force production, ie, quick muscle activation and functional tasks, should be implemented.

Can Symmetry of Single-Leg Vertical Jump Height Represent Normal Lower Limb Biomechanics of Athletes After Anterior Cruciate Ligament Reconstruction?

After anterior cruciate ligament reconstruction (ACLR), single-leg horizontal hop distance limb symmetry index (LSI) >90% is recommended as a cutoff point for safe return to sport (RTS). However, athletes after ACLR have abnormal lower limb biomechanics despite an adequate single-leg hop distance LSI, implying that athletes are at high risk of reinjury. Symmetry of single-leg vertical jump height appears to be more difficult to achieve and can be a better representation of knee function than single-leg horizontal hop distance. Athletes after ACLR with single-leg jump height LSI >90% had similar biomechanical characteristics to healthy athletes. Controlled laboratory study. Level 3. A total of 46 athletes after ACLR were divided into low jump height (LJH, jump height LSI <90%, n = 23) and high jump height (HJH, jump height LSI >90%, n = 23) groups according to symmetry of single-leg vertical jump height, while 24 healthy athletes acted as a control (CONT) group. One-way analysis of variance was used to compare the kinematic and kinetic characteristics of the LJH, HJH, and CONT groups during single-leg vertical jump. Both the LJH and HJH groups demonstrated greater limb asymmetry (lower LSI) during landing compared with the CONT group in knee extension moment (P < 0.05), peak knee flexion angle (P < 0.05), and knee power (P < 0.05). Symmetry in single-leg vertical jump height does not represent normal lower limb biomechanics in athletes after ACLR. Symmetrical jump height may not signify ideal biomechanical or RTS readiness, but single-leg vertical jump test can be used as a supplement to horizontal hop test or other functional tests to reduce the likelihood of false-negative results in the absence of detailed biomechanical evaluation.

Therapy-based expert system on function and postural stability after anterior cruciate ligament reconstruction: a pilot study

PurposeWii Fit exergames have been less commonly used for the rehabilitation of athletes after Anterior Cruciate Ligament Reconstruction (ACLR). This study aims to investigate the effects of an expert system using Wii Fit exergames compared to conventional rehabilitation following ACLR. A forward-chaining rule-based expert system was developed which proposed a rehabilitation program that included the number and type of exercise in terms of difficulty and ease and the duration of each exercise in a progressive manner according to the patient's physical condition.Materials and methodsTwenty eligible athletes aged 20–30 who underwent ACLR were enrolled in this study and randomly assigned to two groups; and received 12 sessions of either Wii Fit exergames as Wii group (n = 10) or conventional rehabilitation as CL group (n = 10).ResultsThe main outcomes consisted of pain (Visual Analogue Scale (VAS)), knee effusion, knee flexion range (KFR), thigh girth (TG), single-leg hop for distance (SLHD), and for time (SLHT), static and dynamic balance tests. Both groups had considerable improvement in all outcomes, also there were significantly differences between Wii and CL groups as follows; VAS (P < 0.001), knee effusion (P < 0.001), TG (P = 0.001), KFR (P = 0.012), static balance in stable position (P < 0.001) and in unstable position (P = 0.001), dynamic balance in the anterior (P < 0.001), posteromedial (P < 0.001), posterolateral (P = 0.004) directions, symmetry index of SLHD (P < 0.001) and symmetry index of SLHT (P = 0.013).ConclusionsThe findings showed that using Wii Fit exergames in post-ACLR patients reduced pain and effusion while also improving function and balance significantly. Iranian Registry of Clinical Trials registration number is IRCT20191013045090N1, and the registration date is 03-03-2020.

Content validity, interpretability, and internal consistency of the "Quality First" assessment to evaluate movement quality in hop tests following ACL rehabilitation. A cross-sectional study.

Current approaches fail to adequately identify sport readiness after anterior cruciate ligament (ACL) rehabilitation. Altered landing biomechanics after ACL reconstruction are associated with increased risk of a noncontact ACL reinjury. There is a lack of objective factors to screen for deficient movement patterns. Therefore, the aim of this study was to investigate content validity, interpretability, and internal consistency for the newly developed "Quality First" assessment to evaluate movement quality during hop tests in patients after ACL rehabilitation. Participants in this cross-sectional study were recruited in collaboration with the Altius Swiss Sportmed Center in Rheinfelden, Switzerland. After a successful ACL reconstruction, the movement quality of 50 hop test batteries was evaluated between 6 and 24 months postoperatively with the "Quality First" assessment. Content validity was assessed from the perspective of professionals. To check the interpretability, classical test theory was employed. Cronbach's α was calculated to evaluate internal consistency. Content validity resulted in the inclusion of three different hop tests (single-leg hop for distance, vertical hop, and side hop). The "Quality First" assessment is enabled to evaluate movement quality in the sagittal, vertical, and the transversal plane. After the exclusion process, the "Quality First" assessment was free from floor and ceiling effects and obtained a sufficient Cronbach's α. The final version consists of 15 items, rated on a 4-point scale. By means of further validations, the "Quality First" assessment could offer a possibility to evaluate movement quality after ACL rehabilitation during hop tests.

Comparison of Patient-Reported Outcomes, Strength, and Functional Performance in Primary Versus Revision Anterior Cruciate Ligament Reconstruction

Background: Clinical outcomes after revision anterior cruciate ligament reconstruction (ACLR) are not well understood. Hypothesis: Patients undergoing revision ACLR would demonstrate worse patient-reported outcomes and worse limb symmetry compared with a cohort undergoing primary ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: 672 participants (373 with primary ACLR, 111 with revision ACLR, and 188 uninjured) completed functional testing at a single academic medical center. Descriptive information, operative variables, and patient-reported outcomes (International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Tegner Activity Scale score) were assessed for each patient. Quadriceps and hamstring strength tests were conducted using a Biodex System 3 Dynamometer. Single-leg hop for distance, triple hop test, and the 6-m timed hop test were also assessed. Limb symmetry index (LSI) between the ACLR limb and contralateral limb was calculated for strength and hop testing. Normalized peak torque (N·m/kg) was calculated for strength testing. Results: No differences were found in group characteristics, excluding body mass (P < .001), or in patient-reported outcomes. There were no interactions between revision status, graft type, and sex. Knee extension LSI was inferior (P < .001) in participants who had undergone primary (73.0% ± 15.0%) and revision (77.2% ± 19.1%) ACLR compared with healthy, uninjured participants (98.8% ± 10.4%). Knee flexion LSI was inferior (P = .04) in the primary group (97.4% ± 18.4%) compared with the revision group (101.9% ± 18.5%). Difference in knee flexion LSI between the uninjured and primary groups, as well as between the uninjured and revision groups, did not reach statistical significance. Hop LSI outcomes were significantly different across all groups (P < .001). Between-group differences in extension in the involved limb (P < .001) were noted, as the uninjured group exhibited stronger knee extension (2.16 ± 0.46 N·m/kg) than the primary group (1.67 ± 0.47 N·m/kg) and the revision group (1.78 ± 0.48 N·m/kg). As well, differences in flexion in the involved limb (P = .01) were found, as the revision group exhibited stronger knee flexion (1.06 ± 0.25 N·m/kg) than the primary group (0.97 ± 0.29 N·m/kg) and the uninjured group (0.98 ± 0.24 N·m/kg). Conclusion: At 7 months postoperatively, patients who had undergone revision ACLR did not demonstrate inferior patient-reported outcomes, limb symmetry, strength, or functional performance compared with patients who had undergone primary ACLR. Patients who had undergone revision ACLR exhibited greater strength and LSI than their counterparts with primary ACLR, but these parameters were still inferior to those of uninjured controls.