A Compound Hop Index for Assessing Soccer Players’ Performance

Athletes regularly have to pass a series of tests, among which one of the most frequently used functional performance measures are single-leg hop tests. As the collected individual results of tests constitute a large amount of data, strategies to decrease the amount of data without reducing the number of performed tests are being searched for. Therefore, the study aimed to present an effective method to reduce the hop-test battery data to a single score, namely, the Compound Hop Index (CHI) in the example of a soccer team. A male, first-league soccer team performed a battery of commonly used single-leg hop tests, including single hop and triple hop for distance tests and the six-meter timed hop test. Gathered data, including Limb Symmetry Indexes of the three tests, normalized to body height for the single- and triple-hop-tests distance separately for right and left legs, and the time of the six-meter timed hop test separately for right and left legs were standardized to z-scores. Consecutively, the z-scores were averaged and formed CHI. The developed CHI represents a novel score derived from the average of z-scores that significantly reduces, clarifies, and organizes the hop performance-measures data.

Efecto agudo del programa Knäkontroll sobre parámetros del rendimiento físico en jugadores de fútbol de categoría juvenil

El fútbol es un deporte que, por la alta exigencia física que requiere, lleva asociado un elevado riesgo de lesión. Dada la magnitud del problema, los investigadores han optado por diseñar estrategias preventivas que ayuden a minimizar la incidencia de lesión en este deporte. Estas estrategias se han organizado como programas de calentamiento previo a la participación en el deporte. Sin embargo, la evidencia sobre el efecto agudo de estas intervenciones sobre parámetros del rendimiento físico es escasa. Por tanto, el objetivo del presente estudio fue analizar el efecto agudo del programa Knäkontroll (nivel B) sobre parámetros del rendimiento físico en jugadores de fútbol de categoría juvenil. Para ello, se utilizó un diseño cuasi-experimental pre-test y post-test, empleando la estabilidad dinámica de la extremidad inferior (Y-Balance Test), la cinemática de la caída en salto vertical (Tuck Jump Assessment [TJA]), el rango de movimiento articular de la dorsiflexión de tobillo (ROM-Sport), la distancia de salto horizontal unilateral (Single-Legged Hop Tests), y la altura de salto vertical unilateral (Single Leg Countermovement Jump [SLCMJ]) como principales medidas del rendimiento físico. Los resultados mostraron un incremento significativo del rendimiento para todas las variables tras la implementación del programa Knäkontroll, a excepción de la altura en el SLCMJ y la cinemática en el TJA. En conclusión, el programa Knäkontroll se presenta como una estrategia adecuada para su aplicación como calentamiento previo a la práctica del fútbol. No obstante, la inclusión de ejercicios (o variantes) adicionales que trabajen el componente pliométrico podría contribuir a la mejora del desempeño en el salto vertical.

Confidence varies more than time during a change-of-direction task in patients following unilateral ACL reconstruction (180)

Objectives: Psychological outcomes may be important for predicting readiness to return to sport and guiding appropriate treatment intervention during rehabilitation for patients following anterior cruciate ligament (ACL) reconstruction. Motor confidence can vary based on the context or task in which it is measured, and clinician perceptions of patient confidence may not accurately reflect patient confidence for a given athletic task. The purpose of this study was to: 1) determine how confidence varies between the affected and unaffected limb, 2) compare patient-rated confidence with a clinician’s perception of patient confidence during the completion of a change-of-direction (COD) test and 3) determine how performance varies between standard hop and change of direction tests completed at six months following ACL reconstruction. Methods: 46 patients (76.36 ± 11.82 kg, 176.2 ± 8.8 cm, 24.3 ± 7.2 yrs., 19/46 Female; Table 1) completed a functional assessment at six months following ACL reconstruction with a bone-patellar-tendon-bone (n=18), quadriceps tendon (n=13) or hamstring (n=15) graft. Functional testing included the single, triple and triple crossover hops for distance and the timed 505 change-of-direction (505) test. Patients rated their confidence during the 505 tests on a scale from “0”, representing no confidence, to “10”, or complete confidence in their ability to complete the task. A single clinician indicated their perception of the patient’s confidence on a 10 cm visual analog scale, with scores converted to a 0-10 scale for agreement analysis. Results: Patient (unaffected limb median 9 (range 6-10), affected limb median 7 (3-10), Z=-5.842, p<0.001,) and clinician-perceived confidence (unaffected median 8 (3-10), affected median 7 (3-9), Z=-3.52, p<0.001) were lower on the affected limb during the 505 task (Fig 2). There was no difference in median scores between clinician’s and patients rating the affected limb (Z=-0.681, p=0.496), whereas the clinician rated the unaffected limb lower (Z=-5.016, p<0.001; Fig 2). There was minimal to no agreement and correlation between patient and clinician-perceived confidence in either the affected (Κ = -0.090 (95%CI -0.196-0.016), p=0.170; Rs(44) = 0.173, p=0.251) or unaffected limb (Κ = -0.048 (95%CI -0.140-0.044), p=0.346; Rs(44) = 0.12, p=0.428) during the 505 test. Completion time did not differ whether the 180 pivot was performed on the affected or unaffected limb (3.2 ±0.5 s vs. 3.2 ±0.5 s, p=0.858), while large differences in performance in the single (138 ±39 cm vs. 103 ±42 cm, p<0.001), triple (451 ± 114 cm vs. 367 ± 116 cm, p<0.001) and triple crossover hop tests (403 ± 119 cm vs. 324 ± 116 cm, p<0.001) were observed (Fig 3A and B). Consequently there was a main effect of test (F(3,180) = 30.686, p<0.001) when comparing LSI indicating that the 505 LSI (100 ± 5%) was higher than for the three hop tests (73 ± 19%, p<0.001, 81 ± 13%, p<0.001, 80 ± 15%, p<0.001; Fig 4). Conclusions: Clinician’s perceptions of patient confidence may not accurately reflect patient confidence during the 505 test, although this requires validation with a larger population of clinicians over a greater variety of tasks. Both patients and a clinician report lower confidence in their reconstructed knee during the 505 test despite comparable performance between limbs. Measuring time alone during the 505 may not accurately reflect underlying performance impairments, and measures of confidence and consideration of movement strategies or compensations may be required, alongside additional tests of lower extremity dynamic performance. Further research is required to clarify the importance of task-specific motor confidence against measures of readiness (i.e., ACL-RSI) and in the context of facilitating safe return to sport following ACL reconstruction.

Comparison of the effects of Wii and conventional training on functional abilities and neurocognitive function in basketball-players with functional ankle instability: Matched randomized clinical trial

Objective: To compare the effects of Wii and conventional training on functional abilities and neurocognitive function in basketball-players with Functional Ankle Instability (FAI). Design: Single-blind matched randomized clinical trial study. Setting: Outpatients setting. Participants: Fifty-four basketball-players were randomly assigned to the Wii and control group. Interventions: All athletes in the Wii group ( n = 27) performed Wii Fit Plus games; and in the control group ( n = 27), they performed conventional training three days a week for 12 sessions. Main outcome measures: To assess functional performance and neurocognitive function, we used hop tests (8-hop, side hop, and single hop) and Deary-Liewald Reaction Time Task (DLRT), respectively. DLRT measured simple and choice reaction time and error rate. Measures were taken at baseline, four weeks, and eight weeks after baseline. Results: In all 54 athletes completed the study. The results showed no significant differences for all hop tests in between-group comparison but the neurocognitive function showed significant improvements in the Wii group compared to the control group ( P < 0.05). Mean (SD) for 8-hop and side hop tests for the involved limb, and simple and choice reaction time four weeks after baseline in the control group were 10.15 (1.02), 12.36 (1.31), and 339.10 (41.57), 530.52 (53.36), respectively and in the Wii group, were 10.46 (1.23), 12.40 (1.31), and 295.25 (13.16), 431.19 (33.46), respectively. Conclusion: Based on our results, both training protocols were equal to positively affect functional abilities. Besides, Wii training improved neurocognitive function and can be applied in FAI rehabilitation protocols.

Eight-Months After Anterior Cruciate Ligament Reconstruction: Is It Time to Return to Physical Activity?

Background. Return to participation in sport is an important outcome when evaluating the success of anterior cruciate ligament (ACL) reconstruction surgery. A review by Arden et al. (2014) demonstrates that just because an athlete has surgery, it does not automatically mean that they will return to sport. So, the purpose of this study was to assess if patients could return to their pre-injury activity level 8 months after ACLR. Methods. Patients completed IKDC-2000, ACL-RSI questionnaires, underwent FMS, YBT, HOP test sets and drop jump tests, which were evaluated with the LESS. ACL laxity was measured by using a GNRB® device. Participants were 81 patients. They were divided into two groups based on single leg HOP test results. The first group included 30 persons who all had their four single leg HOP test scores above 90%. The second group consisted of 51 persons for whom at least one of the single leg HOP tests scored lower than 90%. Results. IKDC and HOP test results in the first group scored higher than in the second group. Psychological confidence was higher in the first group, who had better HOP test results. For the first group, FMS and LESS results were better than those for the second group. Moderate positive correlation was found between LESS scores and laxity results, FMS, three HOP sub-tests. IKDC had the biggest number of correlations with other tests. Results showed negative and weak correlation with laxity results using 134 N power, as well as positive and moderate correlation with HOP sub-tests, FMS, ACL-RSI. Single HOP for distance, triple HOP for distance, crossover HOP for distance and LESS increased the odds of achieving RTS criteria. No other factors were found to be associated with the accomplishment of reaching RTS criteria after ACLR. Conclusions. The main factor which can help decide if a person can return to their pre-injury level of physical activity are the single leg HOP test and LESS. The use of single leg HOP tests and LESS along with psychological and self-reported evaluations is the best test combination for assessment 8 months after ACLR. Keywords: ACL reconstruction, function tests, return to play, jump tests, psychological readiness.

DEFINING LIMB DOMINANCE: A COMPARISON OF PERFORMANCE-BASED AND SELF-SELECTED MEASURES

Background: Limb dominance implies asymmetrical performance due to preferential strength or motor control within a single limb. While dominance may be easy to define and quantify within the upper extremity, there is currently no consensus as to whether limb dominance exists within the lower limbs, and if it does, how to best define it. While objective differences in limb performance would be the gold-standard for the identification of limb dominance, these methods may not be feasible within injured athletes. Several methods of identifying perceived limb dominance utilizing subjective reporting have been described; however, limb dominance may be task dependent and reports analyzing the correlation between objective and subjective performance are limited, particularly among adolescent athletes. Purpose: The purpose of this study was to test the agreement between performance-based and self-reported measures of limb dominance in three different single leg hopping tasks. Methods: These data were prospectively collected as part of a large cross-sectional study of healthy youth athletes aged 8-16 years-old. Self-selected limb dominance was determined by asking the following question: “Which leg would you use to kick a ball as far as you could?”. Each subject performed a series of single leg hops and 3-trial means of the single hop for distance (SH), timed hop (TH), and vertical hop (VH) were used for analysis. Paired samples t-test or Wilcoxon-Signed Rank test were utilized to identify differences in limb performance for each of the hop tests. Associations between self-selected and performance-based measures of limb dominance were analyzed using Chi-square. Results: A total of 352 subjects (55% male(n=191), mean age=11.1) were included. There was a small but statistically significant difference in side-to-side performance for all hop tests with a mean difference of 2.58cm(p<0.001) for SH, 0.13s(p<0.001) for TH and 0.29cm(p=0.03) for VH. There was limited agreement between self-selected and performance-based limb dominance across all hop tests (55%SH, 54%VH, and 66%TH). Similarly, Chi-square analysis revealed no associations (p>0.05) between self-selected and performance-based limb dominance across all hop test constructs. Conclusions: Although a single limb did perform better on all hop tests, the mean differences were small, and likely not clinically relevant. Perceived limb dominance did not predict performance regardless of hopping task. These findings illustrate that equality of performance can be considered normal for young athletes recovering from lower extremity injury. This information also brings into question the appropriateness of holding the perceived dominant limb to higher standards or accepting lower standards for the non-dominant limb. Tables and Figures: [Table: see text][Figure: see text] References: Goekeler A, Welling W, Benjaminse A. A critical analysis of limb symmetry indices of hop tests in athletes after anterior cruciate ligament reconstruction: a case control study. Orthop Traumatol Surg Res. 2017;103(6):947-951. doi: 10.1016/j.otsr.2017.02.015 Losciale JM, Zdeb RM, Ledbetter L, Reiman MP, Sell TC. The Association Between Passing Return-to-Sport Criteria and Second Anterior Cruciate Ligament Injury Risk: A Systematic Review With Meta-analysis. Journal of Orthopaedic & Sports Physical Therapy. 2019;49(2):43-54. doi:10.2519/jospt.2019.8190 Mulrey CR, Shultz SJ, Ford KR, Nguyen A-D, Taylor JB. Methods of Identifying Limb Dominance in Adolescent Female Basketball Players. Clinical Journal of Sport Medicine. 2018;Publish Ahead of Print. doi:10.1097/jsm.0000000000000589 van Melick N, Meddeler BM, Hoogeboom TJ, Maria W. G. Nijhuis-Van Der Sanden, Cingel REHV. How to determine leg dominance: The agreement between self-reported and observed performance in healthy adults. Plos One. 2017;12(12). doi:10.1371/journal.pone.0189876 Velotta, J. & Weyer, J. & Ramirez, A. & Winstead, J. & Bahamonde, Rafael. Relationship between leg dominance tests and type of task. Portugese J Sport Sci. 2011;11(1035-1038). Wellsandt E, Failla MJ, Snyder-Mackler L. Limb symmetry indexes can overestimate knee function after anterior cruciate ligament injury. J Orthop Sports Phys Ther. 2017;47(5):334-338.

PATIENTS WHO ATTEND FORMAL PHYSICAL THERAPY FOR THE ENTIRE DURATION OF RECOVERY AFTER ACLR DEMONSTRATE EXCELLENT FUNCTIONAL OUTCOMES

Background: Limitations in insurance coverage and higher out-of-pocket expenses create challenges for physical therapists rehabilitating pediatric athletes after anterior cruciate ligament reconstruction (ACLR). While recovery may last 9-12 months, rehabilitation typically lasts <7 months. Unfortunately, research indicates many pediatric athletes have poor functional performance at the time of returning to sports. This may indicate incomplete rehabilitation within our current model of treatment. Understanding how rehabilitation utilization relates to functional outcomes may help optimize physical therapy (PT) treatment for pediatric patients post-ACLR. Purpose: To report the pattern of visit usage and functional outcomes of ACLR patients who were cared for within a large, pediatric specialty care network. Methods: A retrospective study of ACLR patients ≤18 years-old who underwent surgery between December 2016 and August 2019. All subjects must have completed rehabilitation within the sponsoring institutions PT centers and completed a functional hop testing battery, consisting of four single leg hop tests, prior to 10 months post-operative. The frequency of subjects able to achieve ≥90% limb symmetry (LS) on all hop tests was calculated and served as the main outcome of interest. Results: Out of 120 potential subjects, 53 were excluded for missing data, treatment at other facilities or care extending outside the designated time-frame, leaving 67 subjects (mean age 14.6 ± 1.5 SD, 38% female) for analysis. On average, PT began 14 days (range 5-33) post-operatively and subjects attended a mean of 40 visits (range 16-64) throughout 9 months of rehabilitation. The mean (range) number of sessions attended during rehabilitation was as follows: 0-6 weeks: 6 sessions (1-12), 7-12 weeks 10 sessions (2-15), 3 to 6 months 14 sessions (1-25), 6 to 9 months 9 sessions (0-23). Hop testing was completed 8 months post-surgery (range 5-10) with 85% of subjects achieving >90% LS on all tests. Conclusion: Physical therapy at a pediatric specialized center resulted in superior functional performance compared to existing literature. Interestingly, visit frequency was maintained throughout a 9-month period, which is not typical practice. Treatment during this latter phase of rehabilitation, involves advanced plyometric and sports conditioning, which may explain the high level of performance seen. Sampling bias and limitations is sample size, warrant caution in interpreting these results; however this data demonstrates that PT within a specialized setting, encompassing the entire duration of recovery after ACLR, yields excellent functional outcomes. Future investigations, within a larger and diverse sample are necessary to more fully understand these factors.