Single-leg Hop Test Research Articles

The Role of Proprioceptive Training as a Method of Functional Rehabilitation of Ankle Sprains in Futsal Players

Each sports branch is characterized by an increasingly fierce competition on the way to performance, the need to overcome the adversary involving from the athletes an intense effort of speed, strength, endurance, ability to concentrate under stress conditions, all these demands increasing the chances of occurrence of the injuries. The study follows the importance of the implementation of proprioceptive training as a component part of the functional rehabilitation program, thus highlighting itsbeneficial effects: diminishing the symptoms, increasing joint mobility and muscle strength, regaining static and dynamic stability, essential parameters of sportsmen’s reintegration. The following tests were applied to the subject: joint assessment, muscle testing, Single Leg Balance Test (SLB), Single Legged Hop Test (SLH), 6 Meter Timed Hop Test, Star Excursion BalanceTest (SEBT) and evaluation of symptomatology and gait using The Foot and Ankle Disability Index (FADI) Score and Sports Module questionnaire. After applying the rehabilitation program, we found that the subject developed a significant improvement of thebalance on unstable surfaces (trampoline, balance board), maintaining the position in unipodal support for a duration of 4 times greater than after the initial evaluation. Also, the speed of execution for the jumps forwards over the distance of 6 meters was improved, the time difference between testing with the healthy limb (4.39 seconds) and that with the affected limb (4.67 seconds) beingbelow 10%. Therefore, we can conclude that the recovery program led to the elimination of joint instability, the results obtained representing essential indices of functional performance

Neurocognitive challenged hops reduced functional performance relative to traditional hop testing

ObjectiveDetermine the relationship between four foundational single-leg hop tests and respective neurocognitive single-leg hop tests. DesignCross-sectional; SettingUniversity gymnasium. Patients or other participantsTwenty-two participants (9 Male, 13 Female, 20.9 ± 2.5 years, 171.2 ± 11.7 cm, 70.3 ± 11.0 kg) were recruited. Maximum distance was measured for three hop tests (single-leg hop, single-leg crossover hop, single-leg triple hop) and fastest time was measured for the fourth (single-leg 6-m hop) for traditional and neurocognitive conditions. Main outcome measuresPearson correlations were conducted to assess the relationship between the new neurocognitive hop and the analogous traditional hop. One repeated measures MANOVA was conducted for each leg to determine the difference in hop performance between hop conditions (traditional and neurocognitive) for the dependent variables. Alpha level was set at α < 0.05. ResultsCorrelations ranged from 0.86 to 0.92 between traditional and neurocognitive hop tests. The repeated measures MANOVA was significant for condition for both legs (p < 0.05). Specifically, the crossover hop (average percent decrease 10.37%), triple hop (average percent decrease 7.13%), and 6-m hop (average percent decrease 81.67%) were statistically different between traditional and neurocognitive conditions (p < 0.05). ConclusionThe addition of neurocognitive reactive and anticipatory components to simulate more sport specific scenarios may improve functional testing for return to sport.

Relationship Between Isokinetic Muscle Strength and Functional Tests in Chronic Ankle Instability

Isokinetic muscle strength measurements and functional tests are usually performed to evaluate ankle condition in chronic ankle instability (CAI), yet there is no clear demonstration of the relationship between isokinetic muscle strength and functional tests. The objective of this study was to evaluate the relationship between isokinetic muscle strength and functional tests in CAI. Between April 2014 and August 2016, 103 patients with unilateral CAI were studied. Single-leg balance, single-heel raise, and single-leg squat tests were performed for static balancing assessment. Single-leg hop, double-leg jump, and sidestep tests were performed for dynamic balancing assessment. The isokinetic muscle strength of both ankles was measured using a dynamometer. The involved ankle showed lower muscle strength in inversion than the uninvolved ankle, while eversion, dorsiflexion, and plantarflexion muscle strength had no significant differences between ankles. There were significant correlations between the isokinetic muscle strength of inversion and the single-leg balance test, single-heel raise test, and sidestep test (Pearson's r; 0.246, 0.514, and 0.229 at 30°/second; 0.288, 0.473, and 0.239 at 180°/second, respectively). The single leg balance, single heel raise, and sidestep tests are useful to assess not only ankle functional performance but also isokinetic muscle strength. Among these tests, the single heel raise test was the most reliable test to reflect muscle strength deficiency in CAI.

Anterior cruciate ligament reconstructed females who pass or fail a functional test battery do not exhibit differences in knee joint landing biomechanics asymmetry before and after exercise.

A functional test battery (FTB) has been proposed to evaluate the readiness of return to activity after ACLR. However, there is limited evidence documenting the usefulness of an FTB. Therefore, the purpose of the current investigation was to compare knee joint landing biomechanics asymmetry during double-leg jump landing (DLJL) and single-leg jump cutting (SLJC) between healthy females and ACLR females who pass (ACLR-pass) or fail (ACLR-fail) an FTB before and after the completion of a sustained exercise protocol. Eighteen ACLR females (ten ACLR-pass and eight ACLR-fail) and twelve healthy females performed an FTB including The 2000 International Knee Documentation Committee Subjective Knee Evaluation Form, the Knee Outcome Survey Activities of Daily Living Scale, quadriceps strength, and single-leg hop tests. DLJL and SLJC knee joint biomechanics asymmetry were measured before and after exercise. During DLJL, there were significant main effects of group on peak anterior tibial shear force (ATSF) asymmetry [F(2,27) = 3.86, p < 0.05, [Formula: see text] = 0.214] and peak vertical ground reaction force (vGRF) asymmetry [F(2,27) = 3.34, p = 0.05, [Formula: see text] = 0.198]. During SLJC, there was a significant group main effect for peak ATSF asymmetry [F(2,27) = 3.494, p = 0.04, [Formula: see text] = 0.206]. ACLR-fail exhibited greater asymmetry in peak ATSF during DLJL and SLJC compared to healthy females. In addition, ACLR-pass exhibited greater asymmetry in peak ATSF and peak vGRF during DLJL and SLJC, respectively, compared to healthy females. However, ACLR-fail did not exhibit any significant differences in landing biomechanics asymmetry during either task compared with ACLR-pass. Furthermore, the completion of a sustained exercise protocol did not affect knee joint landing biomechanics asymmetry across groups. II.

Prevalence and magnitude of preseason clinically-significant single-leg balance and hop test asymmetries in an English adult netball club

ObjectivesSide-to-side asymmetry of lower-limb motor-performance is associated with increased noncontact injury risk in agility-sports. Side-to-side symmetry-analyses using single-leg balance and hop tests has not been reported for community-level adult netball players. The purpose of this study was to perform preseason side-to-side symmetry-analyses using eyes-closed-balance (ECB), triple-hop-for-distance (THD), single-hop-for-distance (SHD), and vertical-hop (VH) tests. DesignCross-sectional; SettingCommunity-level adult netball club. ParticipantsTwenty-three female players (age 28.7 ± 6.2yr; height 171.6 ± 7.0 cm; mass 68.2 ± 9.8 kg). Main outcome measuresRight-left group-level comparisons (paired t-test) and individual-level comparisons (absolute-asymmetry (%)). A limb symmetry index was calculated for each test and a clinically-significant absolute-asymmetry defined as >10%. Clinically-significant absolute-asymmetry prevalence (%) was computed for each test. ResultsThere were no right-left significant differences for any test. Maximum absolute-asymmetries for the ECB, THD, SHD, and VH were 93.3%, 15.2%, 16.7%, and 60.3%, respectively. The prevalence of clinically-significant absolute-asymmetries for the ECB, THD, SHD, and VH was 91.3%, 8.7%, 8.7%, and 52.2%, respectively. ConclusionsGroup-level comparisons with statistical tests fail to expose the extent of clinically-significant absolute-asymmetries. Most players demonstrated preseason clinically-significant absolute-asymmetries for the ECB and VH tests. Preseason clinically-significant absolute-asymmetries that may predispose increased lower-limb noncontact injury risk are widespread in a community-level adult netball club.

Test–retest reliability and discriminative ability of forward, medial and rotational single-leg hop tests

BackgroundSingle-leg hop tests are commonly performed in the forward direction to evaluate functional performance. However, athletes move in multiple directions during pivoting sports. The first aim of this study was to examine test–retest reliability of single-leg hop tests in the forward, medial and rotational direction in non-injured athletes. Second, the discriminative ability to detect leg asymmetries with these hop tests in anterior cruciate ligament (ACL) reconstructed athletes was determined. MethodsSixteen recreational non-injured participants (eight females, eight males; 22.4 ± 1.9 years) were tested twice (one-week interval) and performed the single hop for distance (SH), triple hop for distance (TH), medial side triple hop for distance (MSTH) and 90° medial rotation hop for distance (MRH). Intraclass correlation coefficients (ICCs), standard errors of measurement (SEM) and smallest detectable differences (SDD) were calculated. Discriminative ability was determined in 32 ACL-reconstructed participants (four females, 28 males; 24.4 ± 4.6 years; six months postoperative) who performed the same hop tests once. ResultsThe ICCs ranged between 0.93 and 0.98. The SEM and SDD were respectively 2.6–4.1% and 7.2–11.3% of the mean hop distance of the group. The proportion (%) of ACL-reconstructed participants passing the ≥90% limb symmetry cut-off was 62.5 (SH), 59.4 (TH), 40.6 (MSTH) and 46.9 (MRH). ConclusionExcellent test–retest reliability of forward, medial and rotational hop tests was found. This allows clinicians to make informed interpretations of changes in hop test distances when retesting athletes. Medial and rotational hop tests are more likely to show limb asymmetries in ACL-reconstructed participants compared to forward hop tests.

Return to Sports and Clinical Outcomes After Arthroscopic Anatomic Posterior Cruciate Ligament Reconstruction With Remnant Preservation

To evaluate the clinical outcomes of transtibial posterior cruciate ligament reconstruction (PCLR) with remnant preservation in highly active patients and to investigate the rate of return to sports (RTS), quality of sports activities, and patient satisfaction. Patients with a Tegner activity scale of >5 who underwent isolated PCLR from 2013 to 2016 with minimum 2-year follow-up were retrospectively reviewed. Single-bundle PCLR was performed using fresh frozen allograft irradiated with 50kGy. Subjective assessments included the Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity scale. A questionnaire elicited information associated with RTS and satisfaction. Functional tests included isokinetic muscle strength and single-leg hop tests. We evaluated 52patients, with a mean (± standard deviation) follow-up duration of 29.5 ± 8.6months. The subjective assessments andfunctional tests significantly improved postoperatively (all P < .001). Mean time to return to full sports activity was 9.7± 5.1months. Thirty-eight (73.1%) and 45 (86.5%) patients could return to previous sports activities at 9 and 24months, respectively. A sports-experience questionnaire indicated that 48% and 69.2% of the patients were participating with unlimited effort and performance, respectively, and no pain at 9 and 24months. Multivariate analysis indicated that extensor deficit (odds ratio [OR] 4.2, 95% confidence interval [CI] 1.342 to 17.839), flexor deficit at 60°/s (OR 3.8, 95% CI 1.081 to 14.476), Limb Symmetry Index (%) for the single-leg vertical jump test (OR 2.2, 95% CI 1.212 to 9.227), and satisfaction (OR 2.8, 95% CI 1.186 to 10.281) were significantly associated with failure of not returning to preinjury sports activity levels at the 9-month follow-up. Arthroscopic anatomic PCLR with remnant preservation showed high rates of RTS and high patient satisfaction, as well as satisfactory clinical results in highly active patients. This surgical technique could be an effective treatment for grade III posterior cruciate ligament injury in highly active patients. Level IV, therapeutic case series.

Changes in The Functional Parameters of Balance and Lower Extremities of Adolescent Short and Long-Distance Runners After Exercises on Unstable Surfaces

Background. Results from the previous studies indicated benefits of training on unstable surfaces in various populations. Drawing upon them we hypothesized that training on unstable surfaces would help runners improve balance and lower extremity functional indicators.Methods. The study included 20 adolescent athletes from Kaunas sports school “Startas”, aged 12–13 years, boys and girls running short and long distances. Their training consisted of 20 minute exercises on unstable surfaces performed two times a week. Participants were tested before and after applying the program. The tests applied were Y balance test, calf muscle strength testing with a Lafayette dynamometer, Single-legged Hop tests, T-test.Results. Groups of short- and long- distance runners had better (p &lt; .05) calf muscle strength of both legs after exercises on unstable surfaces program. Both groups also improved 6 m HOP test results of both lower extremities (p &lt; .05). Some of the dynamic balance indicators statistically significantly improved after exercises on unstable surfaces in the groups of short- and long- distance adolescent runners. T-test results after exercises on unstable surface program improved (p &lt; .05) in long- distance runner group (from 14.03 (12.44; 14.95; 13.85) s to 13.94 (12.36; 14.52; 13.65) s) and there were differences between short- and long- distance runner groups before and after exercises on unstable surfaces (p &lt; .05).Conclusion. This research showed that training on unstable surfaces helps runners to improve balance and lower extremity functional indicators and we recommend to include exercises on unstable surfaces to their training.

Isokinetic eccentric training is more effective than constant load eccentric training on the quadriceps rehabilitation following partial meniscectomy: A randomized clinical trial

ObjectivesTo compare the effects of conventional (constant load) eccentric training and isokinetic eccentric training on quadriceps muscle mass, strength and functionality of recreational athletes following partial meniscectomy. DesignRandomized controlled trial. SettingXXXX, Brazil. Participants32 recreational male athletes (∼27 years old) who underwent partial meniscectomy performed a 6-week quadriceps strength training program in one of the experimental groups: conventional group (CG) or icokinetic group (IG). Main outcome measuresQuadriceps muscle mass, strength, and patients’ objective and self-reported function. ResultsBoth groups enhanced muscle mass, strength and functionality outcomes. The IG presented higher increases than CG for muscle mass (ES = 0.99–1.41), strength (ES = 1.48–2.35), and Lysholm score (ES = 1.0). The magnitude-based inference supports that results ‘very likely’ or ‘almost certainly’ favour IG compared to CG for all outcomes, except for the single leg hop test (i.e., between-group similar change). ConclusionAfter partial meniscectomy, isokinetic eccentric training is more effective than conventional eccentric training to restore quadriceps muscle mass, strength, and functional capacity.

Isokinetic eccentric training is more effective than constant load eccentric training for quadriceps rehabilitation following anterior cruciate ligament reconstruction: a randomized controlled trial

ObjectiveTo compare the effects of conventional (constant load) eccentric training and isokinetic eccentric training on quadriceps muscle mass, strength and functional performance in recreational athletes following anterior cruciate ligament (ACL) reconstruction. MethodsThirty recreational male athletes (25 years old) undergoing ACL reconstruction received a standard rehabilitation program. Volunteers were randomized to conventional group (CG; n = 15) or isokinetic group (IG; n = 15) to be engaged in a 6-week (2 sessions/week) quadriceps eccentric training program at the extensor chair or at the isokinetic dynamometer, respectively. Assessments of quadriceps muscle mass (through magnetic resonance imaging), strength (through isokinetic dynamometry) and self-aware functionality (through questionnaire) were performed before and after the training programs. Single leg hop test performance was assessed only at post-training evaluation. ResultsIG had significantly higher improvements than CG (p < 0.05) for all muscle mass outcomes (+17–23% vs. +5–9%), as well as for isometric (+34% vs. +20%) and eccentric (+85% vs. +23%) peak torques. There was no between-group difference (p > 0.05) for concentric peak torque, Lysholm score, and single leg hop test. ConclusionIsokinetic eccentric training promotes greater responses than conventional eccentric training on quadriceps muscle mass and strength of recreational athletes following ACL reconstruction.

Development of a Concise Lower Extremity Physical Performance Test Set for Return to Sport Decision-Making in Pediatric Populations

Objectives: Physical performance tests (PPT’s) are used to assess lower extremity function in pediatric populations. Common PPT’s include the lower quarter Y-balance, stork balance, stork balance on BOSU, single leg squat (SLS), SLS on BOSU, clockwise and counterclockwise quadrant single leg hop (SLH), forward SLH, timed SLH, and triple crossover SLH. Each of these tests assesses distinct performance characteristics, but administration of the full 10-item test battery is not practical. The aims of this analysis were to 1) define the primary underlying components of physical performance assessed by these 10 PPT’s, and 2) derive a reduced item set of PPTs that efficiently and accurately measures performance on each underlying component. Methods: This study included healthy, uninjured volunteers (n=61) between the ages 6 and 17 [mean age = 10.7 ±3.2 years; 33 females (54.1%)]. After a brief warm-up, subjects performed the 10 PPT’s in the same order (listed above), however we randomly assigned the starting test to avoid practice/fatigue effects. Subjects completed 2 trials on each leg for each test with the exception of the SLH tests, which were performed 3 times. We developed a composite score for each test by averaging trials across sides. Prior to item reduction, all Y-balance, and hop tests were normalized to leg length. Item reduction was performed using principal components analysis (PCA) with oblique rotation (Promax) on all 10 tests. We used the Kaiser criterion (eigenvalue &gt; 1) to determine the optimal number of components. Items with loadings &gt; 0.55 were considered for the reduced test item set. Cross-loaded items with &lt; 0.25 absolute difference in loading between components were dropped. If two or more factors loading on the same component were highly correlated (r &gt; 0.7), we dropped the item(s) with the lowest factor loading. Results: The PCA identified 2 components. Component 1 (neuromuscular control/balance) included all balance, single leg squat and quadrant hop test items. The 2 quadrant hop tests were highly correlated (r=0.94), had the second and third lowest factor loadings on the component (&lt;0.78), and were dropped. The SLS test had the lowest factor loading (0.69) and was also dropped. The Stork, Stork BOSU, and SLS BOSU had similar factor loadings (0.79, 0.90, and 0.88, respectively) and did not meet the correlation criterion for removal (all &lt; 0.61). Component 2 (Power) included the forward SLH and Crossover SLH. Each demonstrated high factor loadings (0.94 and 0.79, respectively) and only moderate correlation (r=0.56). The Timed SLH and lower quarter Y-balance did not meet the loading criterion and were dropped. The final 5-item PPT set had a cumulative response variance of 76.0%. The internal consistency (Cronbach α) of the 3-item Component 1 (0.80), 2-item Component 2 (0.72) and overall 5-item set (0.70) were all satisfactory (i.e., &gt; 0.7). Conclusion: The 10 PPT’s measure 2 primary components of lower extremity performance: neuromuscular control/balance and power. These components are most appropriately assessed with the stork balance, stork BOSU, SLS BOSU, forward SLH and triple crossover SLH tests. Of these, the Stork BOSU and forward SLH are most capable of evaluating the 2 components. These findings provide clinicians with efficient options for measuring lower extremity performance in pediatric populations. Future studies should determine whether tests excluded from the reduced-item set provide important prognostic information for clinical outcomes. [Table: see text]

Preseason Functional Performance Test Measures Are Associated With Injury in Female College Volleyball Players.

Preseason functional performance test measures have been associated with noncontact time-loss injury in some athletic populations. However, findings have been equivocal with many studies consisting of heterogeneous populations. To determine if preseason standing long jump and/or single-leg hop test scores are associated with a noncontact time-loss injury to the lower quadrant (LQ = low back or lower-extremities) in female Division III college volleyball (VB) players. Prospective cohort study. National Collegiate Athletic Association Division III female VB teams. A total of 82 female college VB players (age = 18.9 [1.0]y). Standing long jump and single-leg hop test measures were collected at the start of the official preseason. Athletic trainers tracked all time-loss injuries and their mechanisms. Athletes were categorized as at risk if their preseason standing long jump <80% height, bilateral single-leg hop <70% height, and had a SLH side-to-side asymmetry >10%. The noncontact time-loss overall injury rate for the LQ region in at-risk athletes was 13.5 (95% confidence interval [CI], 4.3-31.5) per 1000 athletic exposures. At-risk athletes were significantly more likely to experience a noncontact time-loss injury than VB players in the referent group (rate ratio = 6.2; 95% CI, 1.9-17.2; P = .008). The relative risk of sustaining a noncontact time-loss injury to the LQ was 4 times greater in the at-risk group (relative risk = 4.6; 95% CI, 2.1-10.1; P = .01). At-risk athletes were 6 times more likely to experience a foot or ankle injury (relative risk = 6.3; 95% CI, 2.1-19.2; P = .008). Suboptimal performance on a battery of functional performance tests is associated with a significantly greater risk of noncontact time-loss injury to the LQ in female Division III college VB players.

Strength and Function Across Maturational Levels in Young Athletes at the Time of Return to Sport After ACL Reconstruction.

The impact of maturation on lower extremity strength and function after anterior cruciate ligament reconstruction (ACLR) may help guide future studies of age-specific rehabilitation. Pediatric ACLR patients would demonstrate higher thigh strength symmetry and knee-related function at return to sport (RTS) compared with adolescent and young adult participants who underwent traditional ACLR. Prospective cohort study. Level 2. A total of 144 young athletes at the time of RTS clearance post-ACLR were classified into 3 maturational groups (pediatric, n = 16 with physeal-sparing ACLR [mean age = 12.3 years; range = 9.2-14.6 years]; adolescent, n = 113 [mean age = 16.5 years; range = 14.1-19.8 years]; young adult, n = 15 [mean age = 22.0 years; range = 20.5-24.9 years]). Quadriceps and hamstring strength were measured using an electromechanical dynamometer. Knee-related function was measured using the International Knee Documentation Committee (IKDC) subjective form and single-leg hop tests. The Limb symmetry Index (LSI) was used in calculations for hop and strength tests. Group differences were compared with Kruskal-Wallis tests and Mann-Whitney U post hoc tests. Proportions of participants meeting literature-recommended RTS criterion cutoffs were compared among the groups using chi-square tests. The pediatric group demonstrated higher quadriceps LSI (P = 0.01), IKDC scores (P < 0.01), single-hop LSI (P < 0.01), and crossover-hop LSI (P = 0.02) compared with the young adult group. In addition, the pediatric group demonstrated higher IKDC scores (P < 0.01) and single-hop LSI (P = 0.02) compared with the adolescent group. The adolescent group demonstrated higher IKDC scores (P < 0.01), single-hop LSI (P = 0.02), and crossover-hop LSI (P = 0.03) compared with the young adult group. The proportions of participants meeting all RTS criterion cutoffs were highest in the pediatric group and lowest in the young adult group (P = 0.03). Young athletes at RTS clearance after pediatric ACLR demonstrated higher quadriceps strength symmetry and knee-related function than adolescents and young adults after traditional ACLR. These findings demonstrate the need for further study regarding the impact of these group differences on longitudinal outcomes after ACLR, including successful RTS and risk of second ACL injury.

A Randomized Clinical Trial Comparing Patellar Tendon, Hamstring Tendon, and Double-Bundle ACL Reconstructions: Patient-Reported and Clinical Outcomes at 5-Year Follow-up.

This randomized clinical trial evaluated the 5-year, disease-specific quality-of-life outcomes of patients treated for anterior cruciate ligament (ACL) deficiency with use of a patellar tendon, single-bundle quadruple-stranded hamstring, or double-bundle hamstring reconstruction. Patients (n = 110 per group; 183 male; 14 to 50 years of age) were randomly allocated to anatomically positioned ACL reconstruction with use of a patellar tendon graft (patellar tendon group; mean age, 28.7 years), quadruple-stranded hamstring tendon construct (hamstring tendon group; mean age, 28.5 years), or double-bundle hamstring tendon construct (double-bundle group; mean age, 28.3 years). Computer-generated allocation with varied block randomization was performed intraoperatively. The 5-year primary outcome measure was the Anterior Cruciate Ligament-Quality of Life (ACL-QOL) score, and secondary outcome measures included the International Knee Documentation Committee (IKDC) subjective score and objective grades, pivot shift assessment, range of motion, kneeling pain, Tegner activity scale, Cincinnati Occupational Rating Scale, complete traumatic reruptures, partial traumatic tears, total traumatic reinjuries, and atraumatic graft failures. Three hundred and fifteen patients (95%) completed the 5-year follow-up (4 withdrawals, and 11 lost to follow-up). ACL-QOL scores increased significantly from baseline for all groups (p < 0.0001), but mean scores at 5 years did not differ among the groups (p = 0.548): mean (and standard deviation) of 82.5 ± 17.9 (95% confidence interval [CI], 79.0 to 86.0) for patellar tendon, 83.9 ± 18.2 (95% CI, 80.3 to 87.4) for hamstring tendon, and 81.1 ± 19.3 (95% CI, 77.4 to 84.8) for double-bundle. The proportions of patients at 5 years with a pivot shift grade of ≥2 (12% for patellar tendon, 16% for hamstring tendon, and 22% for double-bundle; p = 0.149) and with normal and nearly normal knees per IKDC grade (87%, 82%, and 75% for the 3 groups, respectively; p = 0.093) trended in favor of patellar tendon reconstruction. No differences were seen for the IKDC subjective scores, knee range of motion including passive extension deficits, the single leg hop test, Cincinnati Occupational Rating scores, and Tegner activity levels. Kneeling pain was more common with patellar tendon reconstruction (10% of patients compared with 4% for hamstring tendon and 2% for double-bundle; p = 0.029). For hamstring tendon and double-bundle reconstructions, there were trends toward more complete traumatic reruptures (4% for patellar tendon, 10% for hamstring tendon, and 10% for double-bundle; p = 0.145) and partial traumatic tears (0%, 5%, and 6%, respectively; p = 0.059), with significantly fewer combined traumatic reinjuries in the patellar tendon group (4 patients compared with 16 for hamstring tendon and 17 for double-bundle; p = 0.010). Atraumatic graft failure (pivot shift grade of ≥2) was found for 10% of the patients. At 5 years, we found no significant difference in the quality-of-life outcome among the patellar tendon, hamstring tendon, and double-bundle techniques for ACL reconstruction. Significantly more patients in the hamstring tendon and double-bundle groups experienced traumatic graft reinjury compared with the patellar tendon group. There was a trend toward a higher percentage with normal and nearly normal IKDC grades in the patellar tendon group compared with hamstring tendon and double-bundle groups. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Changes In Complexity At Maximal Speeds May Not Influence Functional Performance Immediately After: Pilot Study

Regulatory statistics have been previously used to quantify nonlinear characteristics of gait and infer changes in central regulation of movement. Evaluating changes in movement complexity under varying running conditions is essential as alterations in central regulation may influence performance. However, few studies have characterized movement complexity during functional performance tests. PURPOSE: To quantify changes in complexity during an incremental running test to max speed, and during a single leg hop (SLH) test performed immediately before and after. METHODS: Seven healthy runners (25.8±4.9 yrs) performed a 30s SLH test before and after an incremental running test on a motorized treadmill using 4-minute stages (preferred, 10, 12, 14, 16, 18km/h) until volitional exhaustion. Three-dimensional accelerations of the pelvis were recorded using a triaxial accelerometer (100Hz, G-Walk, BTS Bioengineering, Milan, IT) fixed to the pelvis. The last 30s of each running speed and SLH were analyzed using multiscale entropy (MSE) across 5 time scales. Sample entropy estimates (m=2, r=.2) for each scaled time series were summed across all scales to compute complexity index (CI). Paired t-test were employed to compare CI measured from SLH tests and repeated measures ANOVAs with a Bonferroni correction were employed to compare differences in CI between stages for each participant. If significant, Dunnett’s test was employed to compare fastest and slowest stages with preferred. Vertical accelerations are reported. RESULTS: Testing was completed by runners as follows: stage 4 N=7, stage 5 N=5, stage 6 N=3. Mean differences in CI were significant for 4 of 7 runners (p<0.007). Post hoc analyses revealed greater CI in the final stage versus preferred (∆0.62±0.1; ∆1.11±0.01; ∆0.35±0.03; ∆0.49±0.07, p<0.01) while no differences were observed in the slowest stage. No change in SLH CI was found between pre- vs post-run tests (p=0.33, 2.25±0.9 vs 2.14±0.7). CONCLUSION: At maximal speeds, an increase in system adaptability was observed compared to preferred running, however, this increase was not transferred to functional performance immediately after. An increase in complexity during perturbed running and not hopping may be due to dissimilarities in task difficulty and constraint type experienced by the runners.

Gait Asymmetry Can Predict Functional Performance Post ACL Reconstruction: A Pilot Study

Wearable inertial sensors are practical and inexpensive technology that can be used to detect gait asymmetries following anterior cruciate ligament reconstruction (ACLR). Specifically, individuals after ACLR walk with asymmetries in shank angular velocity (SAV) during landing, which may be indicative of abnormal knee joint loading. However, it is unknown whether these asymmetries in SAV detected at early stage of rehabilitation can predict functional performance at 6 months after ACLR. PURPOSE: To investigate whether SAV asymmetries during walking at 4 months after surgery can predict return-to-activity criteria at 6 months in individuals with ACLR. METHODS: Fourteen individuals (8 females; age= 27.79±7.9 y) with primary unilateral ACLR participated in the study. Participants were instructed to walk at a self-selected speed along a 12-meter straight walkway at 4 months after surgery. SAV peak was calculated bilaterally during landing as the first negative peak value after heel strike in the sagittal plane. The average SAV peak was calculated for each limb. At 6 months after surgery, participants completed return-to-activity criteria testing (isometric quadriceps index, single-legged hop tests, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), and Global Rating Score (GRS)). Inter-limb symmetry (ACLR limb/uninjured limb*100) was calculated for SAV peak and functional measures. Linear regression models were used to determine whether SAV peak at 4 months would predict functional performance at 6 months following surgery. RESULTS: Asymmetry in SAV at 4 months was a significant predictor for asymmetries in the isometric quadriceps strength (r2=0.39, p=.02), single hop for distance (r2=0.36, p=.02), triple hop for distance (r2=0.34, p=.03), and triple-crossover hop for distance (r2=0.51, p=.001), but not for the 6-meter timed hop (r2=0.17, p=.14) at 6 months. Greater SAV asymmetry was a significant predictor for worse scores on the KOS-ADLS (r2=0.49, p=.006) and GRS (r2=0.46, p=.008). CONCLUSIONS: This pilot study showed that gait asymmetry detected by inertial sensors at early stage of rehabilitation can predict functional performance at 6 months after ACLR. Implementing these sensors in clinical practice may help clinicians to monitor gait on a regular basis during rehabilitation.

Step down tests are the tasks that most differentiate the kinematics of women with patellofemoral pain compared to asymptomatic controls

BackgroundStudies evaluating kinematics lead to different conclusions, not all changes appear in all assessed tasks and in all subgroups of patients with patellofemoral pain (PFP). The inconsistencies between studies could be reduced if we knew which task separates patients best from healthy controls. Research questionIdentify which functional task, between gait, forward step down (FSD), lateral step down (LSD), stair ascent and descent and propulsion and landing phase of the single leg hop test (SLHT), differentiates the three-dimensional kinematics of women with patellofemoral pain from asymptomatic women. MethodsThis cross-sectional study evaluated thirty-five PFP and thirty-five asymptomatic women during the execution of the following tasks: gait, FSD, LSD, stair ascent and descent and the propulsion and landing phase of single leg hop test. Frontal, sagittal and transverse plane angles of the trunk, pelvis and hip, frontal and sagittal plane angles of the knee, ankle dorsiflexion, foot progression angle and hindfoot eversion were analyzed through the Movement Deviation Profile (MDP). To compare the groups, the multivariate analysis with Bonferroni post hoc test were used, with a significance level of p < 0.01. To identify which task presented the most difference between the groups, the Z-score of the mean MDP was calculated. ResultsFor all tasks, the groups presented significant differences. According to the Z-score, the groups got farther apart considering the MDP for each task in the following order: LSD (7.97), FSD (7.62), landing phase of SLHT (3.43), gait (2.85), propulsion phase of SLHT (1.64), descending stairs (1.63) and ascending stairs (1.00). SignificanceWe suggest that step down tests should be included in the assessment of PFP patients, since these tests most differentiate the kinematics of women with and without PFP. Identifying the tasks with the highest sensitivity to detect the kinematic differences is expected to improve clinical decision-making.

Hop Testing Lacks Strong Association With Key Outcome Variables After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background: Single-legged hop tests are commonly used assessments in return to sport (RTS) testing after anterior cruciate ligament reconstruction (ACLR). Although these tests are commonly used, their predictive validity has not yet been established. Purpose: To determine the strength of association between hop testing and RTS, knee reinjury, subjective report of knee function, and posttraumatic knee osteoarthritis (PTOA) after primary ACLR. Secondarily, to determine whether hop testing is able to predict a favorable result on the same outcome variables. Study Design: Systematic review. Methods: A systematic, computer-assisted literature search was performed in PubMed/MEDLINE, CINAHL, EMBASE, SPORTDiscus, Cochrane Library, and ClinicalTrials.gov. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed when conducting and reporting this review. Primary outcome variables for this review were self-report of knee function, return to preinjury level of activity, presence of reinjury, and presence of PTOA. The Oxford Centre for Evidence-Based Medicine Levels of Evidence tool was used to assess the level of evidence for each included study. Quality assessment of each included study was performed through use of a modified Downs and Black scale. Available metrics were tabulated based on outcome variables. Results: Overall, 21 studies (4476 patients) met inclusion for this review. The majority of evidence (95.2%) was of moderate to high methodologic quality. The most commonly associated outcome measure was the International Knee Documentation Committee (IKDC) score, with Pearson correlation coefficients ranging from 0.20 to 0.60. The strength of association between the Knee injury and Osteoarthritis Outcome Score (KOOS) and hop testing ranged from −0.10 to 0.62 in 4 studies. In all, 10 studies examined the relationship between hop testing and RTS, with variable association statistics reported. No meaningful association was found between hop testing and knee reinjury in 2 studies. Worse preoperative hop testing was associated with PTOA in 1 study. Conclusion: Hop testing appears to possess fair association to subjective report of knee function measured by the KOOS and IKDC and a patient’s ability to RTS after ACLR. Insufficient evidence is available to determine the relationship between hop testing and PTOA and knee reinjury. Predictive validity cannot be established based on available literature.

The Effects of Instruction Exercises on Performance and Kinetic Factors Associated With Lower-Extremity Injury in Landing After Volleyball Blocks.

Female volleyball players are more predisposed to anterior cruciate ligament injury in comparison with their male counterparts. Recent research on anterior cruciate ligament injury prevention strategies has shown the positive results of adopting the external focus (EF) of attention in sports. To determine the effect of 6-week EF instruction exercises on performance and kinetic factors associated with lower-extremity injury in landing after the volleyball blocks of female athletes. Pretest and posttest control study. University research laboratory. Thirty-two female volleyball players (18-24y old) from the same team randomly divided into experimental (n = 16) and control (n = 16) groups. The experimental group performed a 6-week exercise program with EF instructions. The control group continued its regular volleyball team schedule. To assess function, single-leg triple hop test for distance was used. A force plate was used to evaluate kinetic variables including vertical ground reaction forces, the rate of loading, and dynamic postural stability index. All data were assessed at baseline and after the intervention. There was a significant increase in single-leg triple hop test (P < .05) and in the first and second peak ground reaction force, rate of loadings, dynamic postural stability index (P < .05). According to the results of this study, anterior cruciate ligament injury prevention programs should incorporate EF instruction exercises to enhance the kinetics and to increase athletes' functional performance.

Generalized joint hypermobility does not influence clinical outcomes following isolated MPFL reconstruction for patellofemoral instability.

Generalized joint hypermobility (GJH) has frequently been described as a risk factor for patellofemoral instability; however, only a few primary research studies have demonstrated any evidence of a relationship. The primary purpose of this study was to determine if isolated proximal soft tissue stabilization for patellofemoral instability is as successful in patients with GJH compared those without, as measured by disease-specific quality-of-life (QOL), symptom scores and functional outcomes. The secondary purpose was to determine if clinical and patient-reported outcomes were influenced by patient demographic factors in the presence of joint hypermobility. Between 2009 and 2014, data were collected on 174/193 knees (92% follow-up) following an isolated medial patellofemoral ligament reconstruction (MPFL-R). Patients with a Beighton score of 4 or greater were classified as positive for GJH, and any score of 3 or less was classified as negative. Pre- and post-operative Banff Patella Instability Instrument (BPII) scores were compared using a two-sample t test to determine the influence of GJH on QOL. The relationship between the Beighton score, and demographic and clinical factors was explored using correlational analysis. Functional testing including balance and single-leg hop testing was conducted 1and 2years post-operatively. Limb symmetry and mean limb-to-limb performance differences were calculated. In this cohort of isolated MPFL reconstructions, 55.1% had a positive Beighton score. There were seven surgical failures (3.6%). There was no evidence of a relationship between a positive Beighton score and pre-operative BPII scores, post-operative BPII scores or post-operative symptom scores. GJH did not correlate significantly with any post-operative functional testing measures. A positive Beighton score was inversely related to patient age and more prevalent in females. This study determined that the presence of GJH did not influence disease-specific quality of life, physical symptom score or functional outcomes following MPFL reconstruction. III.