Functional Hop Tests Research Articles

Return to Sport: When to Resume Full Activity After an ACL Surgery.

Although surgery to fix a torn anterior cruciate ligament (ACL) is common, knowing when it is safe to return to activities and sports after ACL reconstruction is not always clear. As part of their rehabilitation, patients often fill out surveys, such as the International Knee Documentation Committee survey, that ask questions about how patients think they are recovering. It is not clear, though, how well these surveys truly predict an athlete's readiness to get back to activities and sports. A study published in the December 2014 issue of JOSPT provides new insight and evidence-based tools to help answer this question.

Core Stabilization Training After Anterior Cruciate Ligament Reconstruction

Objectives:The aim of this study was to compare the effects of core stabilization exercises and conventional rehabilitation exercises after anterior cruciate ligament reconstruction in terms of knee joint laxity, knee muscle strength, postural stability and functional tests.Methods:Twenty eight patients reconstructed with hamstring tendon were included. Thirteen patients evaluated after a conventional rehabilitation and fifteen after a core stabilization programme. Single-limb postural stability assessment, isokinetic knee muscle strength test, instrumented ligament laxity test, functional hop tests were done to both groups after 16th week. Single-limb postural stability was assessed with stabilometer in both eyes open and eyes-closed conditions. Healthy legs were evaluated as internal controls.Results:Knee flexor and extensor strength indices were not different between groups (p>.05). H/Q strength ratio was different at 180 °/s (p<.05). Knee laxity was not different between groups (p<.05). There was no significant difference in hop distance and hop index between groups (p>.05). Conventional training group had deficit in overall stability score in eyes closed condition (p>.05), but core stabilization group did not have any postural stability deficit (p>.05).Conclusion:Better H/Q strength ratio was seen in core stabilization group. Core stabilization exercises improved postural stability more than classic rehabilitation.

Strength and functional performance recovery after anterior cruciate ligament reconstruction in preadolescent athletes.

Background:In the skeletally immature population, the incidence of anterior cruciate ligament (ACL) injuries and ACL reconstructions appears to be increasing. Differences in surgical techniques, physiology, and emotional maturity may alter the rehabilitation progression and impact the outcomes when compared with adults. Reports of objective strength recovery and performance-based outcome measures after pediatric ACL reconstruction (ACLR) are limited.Study Design:Retrospective case series.Level of Evidence:Level 4.Methods:All patients that underwent all-epiphyseal ACLR from January 2008 to August 2010 were identified. Isokinetic peak quadriceps/hamstring torque values and functional performance measures in unilateral hopping tasks were extracted and compared with the noninjured limb. A limb symmetry index (LSI) of ≥90% was considered satisfactory.Results:Complete data were available for 16 patients (mean age, 12.28 years; range, 8.51-14.88 years). By a mean 7 months (range, 3.02-12.56 years) postoperatively, only 9 of 16 (56%) were able to achieve a satisfactory LSI for quadriceps strength. For hamstring strength, 15 of 16 (94%) were able to achieve satisfactory LSI. By a mean of 12 months (range, 5.39-24.39 months) postoperatively, only 6 of 16 subjects (38%) were able to achieve satisfactory performance on all functional hop tests. At a mean 15.42 months (range, 8.58-24.39 months) postsurgery, only 4 of 16 (25%) subjects were able to achieve an LSI of ≥90% on all testing parameters.Conclusion:For some pediatric patients, significant strength and functional deficits may be present at greater than 1 year after ACLR. This population may require more prolonged rehabilitation programs to allow for adequate recovery of strength and function because of unique characteristics of normal growth and development.

A-34 Clinical Case Slide - Knee I

Asymmetry in neuromuscular control of the lower extremity has been shown to result in asymmetrical landing patterns, which may increase the risk of anterior cruciate ligament (ACL) injuries. Valid and efficient screening methods are needed to help identify those that may be at greatest risk of ACL injury. While functional hop tests are commonly used to assess asymmetry in the neuromuscular function of the lower extremity, it is unknown whether asymmetries during functional hop tests result in different landing patterns during dynamic tasks. PURPOSE: To compare landing kinematics between limbs during a single leg landing (SLL) task in those who exhibit asymmetry and those who do not exhibit asymmetry in hop distance with the single leg triple hop test (SLTH). METHODS: Nineteen Division I female soccer players (19.2 ± 1.0 yrs, 168.3 ± 6.6 cm, 63.7 ± 5.2 kg) participated in the study. The SLTH reflected the distance traveled following 3 consecutive hops for maximal distance. Three-dimensional trunk, hip, and knee kinematic data were collected during 3 SLL trials. The limb symmetry index (LSI = [preferred limb/non-preferred limb] × 100%) was calculated using the preferred limb as the limb that hopped the furthest. Participants were dichotomized into an asymmetrical (ASYM, n=8, LSI=94.4%) or symmetrical (SYM, n=11, LSI=98.1) group based on the average LSI in the overall sample. Differences in the kinematic variables during the SLL were analyzed via separate repeated measures ANOVA with one-between (LSI group) and one with-in (limb) subject factors. RESULTS: The ASYM group landed in greater hip abduction at initial contact (3.7±0.67°, P=0.016) and went through greater hip adduction (3.5±1.7°, P=0.011) and trunk flexion (4.9±3.3°, P=0.036) compared to the SYM group during the SLL. No significant LSI group-by-limb interactions and no differences between limbs during the SLL were observed. CONCLUSIONS: Asymmetry between limbs observed in a SLTH result in differences in landing kinematics at the hip and trunk during a SLL. This suggests that asymmetry observed in a SLTH might be an effective screening method to identify those that may have decreased neuromuscular control of the hip and core, potentially increasing the risk of ACL injuries.

Asymmetry in a Functional Hop Test Effectively Identifies Differences in Landing Kinematics

Asymmetry in a Functional Hop Test Effectively Identifies Differences in Landing Kinematics

Prognosis of Ankle Syndesmosis Injury

Ankle syndesmosis injury has been associated with persistent pain and prolonged recovery; however, no predictors of prolonged recovery have been identified. The aims of this study were to establish prognosis for ankle syndesmosis injury compared with a lateral ankle sprain and to explore factors associated with prolonged recovery. Participants (n = 63) age 21 ± 3.2 yr, with acute ankle ligament injuries (diagnosed through magnetic resonance imaging), were recruited from 10 sport clubs and sports medicine and physiotherapy clinics in two Australian cities. Follow-up was until full recovery and with preinjury activity level. Time to return to play was compared between injury types using Kaplan-Meier survival curves. Secondary analysis investigated putative factors that increased risk of prolonged recovery. For this analysis, participants unrecovered at 2 wk completed the following: Fear Avoidance Beliefs Questionnaire (FABQ); Star Excursion Balance Test, weight-bearing lunge, and vertical jump (VJ). These variables were correlated with time to recovery using bivariate Pearson's r correlation coefficient. The median recovery time for conservatively treated ankle syndesmosis injury was 62 and 15 d for lateral sprain. The sport-specific subscale scores of the FABQ were significantly higher (P = 0.017) for the ankle syndesmosis group, whereas vertical jump height was lower for this group, (P = 0.052). No baseline variables were strong predictors (r ≥ 0.6) of recovery. Moderate correlations were found for VJ (r = -0.471, P = 0.004) and the sport-specific subscale of the FABQ (r = 0.463, P = 0.004). Conservatively treated ankle syndesmosis injuries took four times longer to recover than lateral ankle sprain. Tests such as VJ and FABQ may identify individuals at risk of prolonged recovery and allow health professionals to determine realistic and appropriate time to recovery.

Medial Patellofemoral Ligament (MPFL) Reconstruction for the Treatment of Patellofemoral Instability

Patellofemoral instability can be a disabling problem. Numerous techniques are employed for its treatment. Medial patellofemoral ligament (MPFL) reconstruction in combination with other procedures has been explored by many orthopedic surgeons. The purpose of the study was to determine the effectiveness of isolated MPFL reconstruction in treating the symptoms associated with patellofemoral instability, preventing recurrence of patella dislocation, and returning patients to preinjury level of activity. This is a case series study. We conducted a clinical follow-up study on 56 knees (49 patients) after MPFL reconstruction for recurrent patellar instability with a mean follow-up of 4.3 years (range, 1.1-6.8). A single MPFL reconstruction technique was performed in all cases. Patient outcomes were evaluated using: International Knee Documentation Committee (IKDC) subjective knee form, Tegner activity score, functional hop test, and radiographs. Mean age at time of surgery was 24 years old (range, 13-49). Females comprised 75% of the sample. Mean interval from injury to surgery was 7.2 ± 8.6 years (range, 51 days-37 years). At follow-up, there were no recurrent dislocations reported, patella subluxation in 6 (11%) cases, and radiographic degenerative changes were none to mild in all patients. The series mean IKDC scores at follow-up was 76.3 ± 19.2 (range, 30-99), and Tegner activity scores were 5.6 ± 2.5. MPFL reconstruction is an option for treating the symptoms of patellar instability, preventing recurrent dislocation, and returning patients near to their preinjury level of activity. The level of evidence is IV.

Biomechanical Comparison Of Double Bundle Versus Single Bundle Anterior Cruciate Ligament Reconstruction Using Three Dimensional Gait Analysis

No differences were detected between anatomic SB and DB ACL reconstructed patients with regard overall tibio-femoral rotation and adduction moments. There has been a recent focus on surgical techniques that more closely approximate the anatomy of the anterior cruciate ligament (ACL). Double bundle techniques have gained popularity but are more surgically demanding, costly and may lead to more complex revision procedures. Outcome measures used in clinical studies may not be sensitive enough to detect a difference between the techniques, therefore more accurate in vivo studies are required. This study utilizes three dimensional gait analysis to compare two groups of patients having undergone either an anatomical single or double bundle ACL reconstruction. It is hypothesised that there will be no significant difference between the two groups with regard tibio-femoral rotation and knee adduction moments. Twenty-eight patients (14 SBACLR, 14 DBACLR) were assessed using a ten-camera Vicon system allowing three dimensional gait analysis. They were each required to perform four tasks: level walking, step descent and immediate pivot, jog and cut and hop and dodge The overall range of tibial rotation and knee adduction moments were recorded for the reconstructed and normal contralateral knee. Other outcome measures including KT-1000, IKDC score and functional hop tests were recorded and clinical tests such as a Lachman and pivot shift were performed. Patient demographics were similar for both groups and all patients were clinically stable and satisfied with their reconstructed knee (IKDC A or B). There were no significant differences for range of tibial rotation between the reconstructed and ACL intact limbs for either the DB or SB groups. Similarly there were no differences between DB and SB groups regarding adduction moments. This paper demonstrates that an anatomical single bundle ACL reconstruction, when compared to the normal contralateral knee, is able to control tibio-femoral rotation and adduction moments as well as a double bundle procedure. The key may be anatomical graft position, not the number of bundles.

Does Preoperative Exercise Influence the Outcome of ACL Reconstruction?

Does preoperative exercise influence the outcome of ACL reconstruction? Although volumes of literature have been generated every year relating to the rehabilitation parameters and protocols to be followed postoperatively, very few studies have addressed the pre operative period of an individual selected to undergo ACL reconstruction. We hypothesized that a structured pre-operative exercise program would enhance postoperative functional outcomes following ACL reconstruction. The objective of the present study was to investigate the effectiveness of a structured pre operative exercise program. A single blind, prospective, randomized controlled study was undertaken. A total of 63 subjects were allocated into two groups. One group performed a structured pre-operative exercise program for 3 weeks (pre-op exercise group, n=32), and the second group did not perform any exercise pre-operatively (No pre-op exercise group, n=31). Both groups underwent an identical postoperative exercise regimen. A range of outcome measures were documented by a blinded assessor postoperatively at 6 weeks, 3 months, 6 months and one year. The preoperative exercise program significantly improved a number of functional outcomes in the group that performed these exercises. Statistically significant differences were observed between the groups in the extension ROM measures at 6 weeks (p=0.02) and 3 months (p=0.01) and in the flexion ROM at 3 months (p=0.02) with the preoperative exercise group achieving better ROM at each of these measurement periods. No significant differences were found between both the groups in pain scores and girth measurements. However, a statistically significant difference was found between the groups in a wide range of subjective and objective functional measures. Statistically significant differences were found between both the groups in Lysholm scores (95.5±3.4 Vs 89.32±5.6, p=0.005) and Tegner activity scores (5.06±0.11Vs 4.2±0.06), p= 0.002) especially in the early postoperative period, with the pre-operative exercise group reporting better scores. Significantly better results were also demonstrated by the pre-operative exercise group at long term in the scales that measured the participation levels. Lower extremity functional scale (LEFS) scores of 76.2±5.07 & 78.5±2.9 for the preoperative exercise group as compared to scores of 72.1±6.6 & 76.2±3.6 for the no-preoperative exercise group at 6 months (p=0.009) & 1 year (p=0.032)respectively were reported. Statistically significant differences were also found between both the groups in the IKDC scores at 6 months (85.9±6.5 Vs 80.9±9.6, p=0.01) and at 1 year (89.7±5.2 Vs 85.6±8.1, p=0.02) postoperatively. The pre-operative exercise group also performed better in the battery of functional hop tests, with statistically significant limb symmetry index scores (LSI %) in the single hop test at 6 months (85±4.3 Vs 80.9±6.6, p=0.005) and 1 year (87.7±3.7 Vs 83.8±7.6, p=0.01) postoperatively. A structured preoperative exercise program resulted in better post operative functional outcomes at the long term.

Asymmetries in Functional Hop Tests, Lower Extremity Kinematics, and Isokinetic Strength Persist 6 to 9 Months Following Anterior Cruciate Ligament Reconstruction

Within-subject and between-subject cross-sectional study. To investigate symmetry in hop-test performance, strength, and lower extremity kinematics 6 to 9 months following anterior cruciate ligament reconstruction (ACLR). Despite the extensive body of literature involving persons following ACLR, no study has comprehensively evaluated measures of strength, lower extremity kinematics, and functional performance of functional hop tests in this population. The subjects were 22 men (mean ± SD age, 28.8 ± 11.2 years) who had ACLR using a bone-patellar tendon-bone autograft 6 to 9 (7.01 ± 0.93) months previously and 22 healthy male controls (age, 24.8 ± 9.1 years). Participants completed a self-report questionnaire and underwent isokinetic strength testing and functional and kinematic assessment of the single-, triple-, and crossover-hop tests. Two-way analyses of variance were used to test for differences between the ACLR group and the control group, and between the 2 lower extremities of the ACLR group. Compared to the control group, the ACLR group had greater isokinetic knee extension torque deficits at all speeds (P ≤.001) and greater performance asymmetry for all 3 hop tests (P<.001). Compared to the noninvolved lower extremity, the involved lower extremity of the ACLR group exhibited less ankle dorsiflexion and knee flexion in the phases of propulsion (P ≤.014) and landing (P ≤.032). When compared to the control group, the involved lower extremity exhibited less ankle dorsiflexion in the propulsion phase (P<.001) but higher hip flexion in the landing phase (P = .014). Six to 9 months following ACLR, patients continue to demonstrate functional hop and isokinetic knee extension deficits, as well as kinematic differences, during the propulsion and landing phases of the hop tests.

Association between preseason functional tests and injuries in youth football: A prospective follow‐up

This prospective cohort study aimed at identifying player-related risk factors for injuries in youth football as determined by extensive preseasonal screening. All male U15-U19 players from a regional football school (season 2007-2008; n = 67) underwent preseason evaluations assessing physical fatigue, emotional stress and injury history (questionnaire), anthropometric variables, general joint laxity (Beighton score), lower limb coordination (functional hop tests), aerobic fitness (shuttle run test), strength of knee extensor and flexor muscles (isokinetic tests), static and dynamic balance (force plate tests), and explosive strength (jump tests on force plate). Football exposure and all football-related injuries (n = 163) were recorded during the entire subsequent season (44 weeks). Total injury incidence was 10.4 injuries/1000 h and was higher in competition than in training [relative risk = 3.3; CI(95%) (2.39; 4.54); P < 0.001]. Lower limb injuries were most frequent (87%). Acute contact injuries represented 37%, while intrinsic (noncontact and chronic) injuries amounted to 63%. Of all the variables tested, only physical fatigue was significantly associated with injury, as revealed by univariate and multivariate analyses. The same result was observed when considering only intrinsic injuries as outcome. A single preseason test session may be of limited interest in the framework of an injury prevention strategy.

CSM 2011 Sports Physical Therapy Section Poster Presentations (Abstracts SPO2175–SPO2193)

CSM 2011 Sports Physical Therapy Section Poster Presentations (Abstracts SPO2175–SPO2193)

The influence of Mulligan ankle taping during balance performance in subjects with unilateral chronic ankle instability

Objective : To determine whether Mulligan ankle tape influenced the performance in subjects with unilateral chronic ankle instability (CAI) during static balance; postural sway recovery patterns after hopping and dynamic tracking balance tasks. Design : A cross-sectional, within-subjects experimental study design between 4 ankle conditions (taped; untaped: injured and uninjured). Participants : 20 volunteer recreational athletes with unilateral CAI were recruited. Means and standard deviations highlighted the athletes' characteristics: age = 23 ± 1 years; height = 173.1 ± 2.4 cm; weight = 69.3±3 kg; Functional Ankle Disability Index (FADI) = 93.5 ± 5.1% and FADI Sport = 84.2 ± 9.4%. Interventions : Mulligan ankle taping. Main Outcome Measurements : Static balance (10 s); postural sway recovery patterns after a 30 s functional hop test (immediately, 30 and 60 s); dynamic tracking balance tasks (wandering, target overshoot and reaction-time). Results : Between the four conditions, static balance showed no significant differences ( p = 0.792); significant changes occurred in postural sway over time ( p < 0.001); no significant changes were reported for the dynamic tracking tasks. Wandering was highly correlated with reaction-time and overshooting ( p < 0.01). Conclusion : Under resting and fatigued conditions, Mulligan ankle taping did not impact on the neuromuscular control during static and dynamic balance in subjects with healthy and unstable ankles.

Three-year Followup Study of Topical Glyceryl Trinitrate Treatment of Chronic Noninsertional Achilles Tendinopathy

Topical glyceryl trinitrate treatment has demonstrated short-term efficacy in chronic noninsertional Achilles tendinopathy. No long-term followup is reported. We aimed to assess if the demonstrated efficacy of this treatment persisted 3 years after discontinuation of therapy. A follow-up study of 52 patients (68 tendons) treated with 6 months of glyceryl trinitrate therapy or placebo was performed 3 years after cessation of therapy. Assessment included pain scores, return to previous activity, the Victorian Institute of Sport Achilles tendon scale (VISA-A), asymptomatic patient outcomes, clinical assessment of tendon tenderness, and functional hop test. Patients treated with topical glyceryl trinitrate had significantly less Achilles tendon tenderness (p = 0.03), and improved VISA-A scores (p = 0.04) than those in the placebo group; 88% (28 of 32 tendons) of patients were completely asymptomatic at 3 years (VISA-A score of 100) compared to 67% (24 of 36 tendons) of patients treated with rehabilitation alone (p = 0.03 with Chi square analysis). Other outcome measures showed nonsignificant trends towards improvement in the glyceryl trinitrate group (pain scores p = 0.07, functional hop test p = 0.07, and return to sport p = 0.16). The mean estimated effect size for all outcome measures was 0.21. Topical glyceryl trinitrate treatment has demonstrated efficacy in treating chronic noninsertional Achilles tendinopathy, and the treatment benefits continue at 3 years. Significant differences in asymptomatic patient outcomes for the glyceryl trinitrate group continue at 3 years, and this is confirmed by the effect size estimate. This suggests that the mechanism of action of topical glyceryl trinitrate on chronic tendinopathies is more than an analgesic effect.

Do early quadriceps exercises affect the outcome of ACL reconstruction? A randomised controlled trial

A prospective, blinded, randomised controlled trial investigated the effectiveness of quadriceps exercises following anterior cruciate ligament reconstruction. A treatment group (Quadriceps exercise group) performed straight leg raises and isometric quadriceps contractions throughout the first two postoperative weeks, and a second group (No quadriceps exercise group) did not. A battery of outcome measures assessed subjects postoperatively at day one, two weeks, and one, three and six months. A total of 103 patients (Quadriceps exercise n = 48, No quadriceps exercise n = 55) commenced the study with 91 subjects available at final follow up (Quadriceps exercise n = 47, No quadriceps exercise n = 44). Performance of quadriceps exercises significantly improved a number of knee flexion and extension range of motion measurements (p = 0.01 to 0.04). No significant differences were found between the two groups at any postoperative period for quadriceps lag (p = 0.36), functional hop testing (p = 0.49 to 0.51), isokinetic quadriceps strength (p = 0.70 to 0.72), the majority of numerical analogue scores (p = 0.1 to 0.94) and Cincinnati scores (p = 0.10 to 0.84). Subjects performing quadriceps exercises reported significantly higher pain scores with exercise on the first postoperative day (p = 0.02). At six months postoperatively, the Quadriceps exercise subjects reported significantly more favourable Cincinnati scores for symptoms (p = 0.005) and problems with sport (p = 0.05). While average knee laxity was not significantly different between treatment groups over time (p = 0.27 to 0.94), quadriceps exercise performance was associated with a significantly lower incidence of abnormal knee laxity. Isometric quadriceps exercises and straight leg raises can be safely prescribed during the first two postoperative weeks and confer advantages for faster recovery of knee range of motion and stability. It remains to be proven whether the magnitude of differences between groups is clinically significant.

Weight-Bearing and Non-Weight-Bearing Knee-Joint Reposition Sense and Functional Performance

Objective:To determine the relationship between weight-bearing (WB) and non-weight-bearing (NWB) joint reposition sense (JRS) and a functional hop test (FH) and to compare performance on these parameters between athletes and nonathletes.Design:Repeated-measures ANOVA and Pearson correlations.Setting:Research laboratory.Participants:40 men (age = 20.8 ± 1.7 y; ht = 176.9 ± 5.8 cm; wt = 82.6 ± 9.5 kg): 20 lacrosse players and 20 nonathletes.Main Outcome Measures:Ability to actively reproduce 30° of knee flexion in the WB and NWB conditions and functional performance on a single-leg crossover-hop test.Results:No significant correlations were observed between JRS and FH in athletes and nonathletes. No significant differences were observed between athletes and nonathletes in JRS. All participants were significantly more accurate at WB than at NWB JRS.Conclusions:There appears to be no relationship between WB or NWB JRS and functional performance, regardless of one’s physical activity level

Test–retest reliability of knee rating scales and functional hop tests one year following anterior cruciate ligament reconstruction

Objectives: The aim of this study was to examine the test–retest reliability of the Cincinnati Knee Rating System and analogue scale, and four hop tests in subjects following anterior cruciate ligament (ACL) reconstruction, and to describe knee function one year following surgery. Design: Within-subject quasi-experimental design for test–retest reliability. Setting: A university rehabilitation laboratory. Participants: Nineteen subjects presenting at 12 months post ACL reconstruction were recruited from two orthopaedic surgeons. Main outcome measures: Knee rating scores, raw performance scores for the 6m timed hop, cross over hop, stair hop and vertical hop, and hop test limb symmetry indices (LSI) were compared on two testing occasions, performed one week apart. Results: Intraclass correlation coefficients (ICC) indicated high test–retest reliability for all measured parameters (0·81–0·98). No significant difference between test occasions was observed for the knee rating scales and vertical hop raw scores. Significant differences were noted for raw scores in the remaining hop tests (P<0·01). The LSI scores for all hop tests were not significantly different between the two occasions. Mean values ranged from 88·8% to 96·6%. Conclusions: The knee rating scales and functional hop tests showed high test–retest reliability in an ACL-reconstructed population, supporting their use for evaluating this specific patient group over different sessions. Reconstructed limb functional performances were within normal limb symmetry values one year following surgery.

Intrarater reliability of selected clinical outcome measures following anterior cruciate ligament reconstruction.

Single group repeated measures following anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the intrarater reliability of selected clinical outcome measures in patients having ACL reconstruction. Several investigations have reported the reliability of isokinetic testing and knee ligament arthrometry. Fewer studies have examined the reliability of lower extremity functional tests, with most of these studies evaluating normal subjects. Fifteen physically active males with unilateral ACL-reconstructed knees were evaluated with the KT-1000, Biodex isokinetic dynamometer, and 3 functional hop tests on 5 occasions. Intraclass correlation coefficients (ICCs) revealed good to high intrarater reliability (ICC > 0.80) of the functional hop tests and isokinetic peak torque values ICCs were higher for the involved limb than the uninvolved limb using the scores from the KT-1000 Manual Maximum Test. The outcome measures examined in this investigation have been shown to be reliable in patients with ACL reconstructions, and support previous investigations in nonimpaired populations. Further research is needed to examine the validity of these postoperative outcome measures in patients with ACL reconstructions.