Prospective Functional Performance Testing and Lower Extremity Injury Incidence in Adolescent Athletes

Abstract

The purpose of this study was to prospectively investigate if a battery of functional performance tests could be used as a preseason screening tool to identify adolescent athletes at risk for sports-related lower extremity injury via comparison of injured and uninjured subjects. Ninety-five adolescent volleyball, basketball and soccer athletes (female, n=62; male, n=38; mean age = 14.4±1.6) participated. Each subject performed a battery of functional performance tests during the preseason, referred to in the present study as the “Lower Extremity Grading System” (LEGS). The LEGS assessment included: triple hop for distance, star excursion balance test, double leg lowering maneuver, drop jump video test, and multi-stage fitness test. Subjects were monitored throughout their designated sport season(s), which consisted of a six-month surveillance period. The schools certified athletic trainer recorded all injuries. Subjects were divided into groups according to gender and injury incidence (acute lower extremity injury vs. uninjured). Univariate general linear model (GLM) was used to assess differences between groups. Pearson product moment correlation coefficients were determined between variables of interest. The receiver-operator characteristic (ROC) analysis was used to determine the cut-off score. The prospective mean LEGS composite scores were significantly lower between the injured and uninjured groups in both genders (males: 19.06±3.59 vs. 21.90±2.44; females: 19.48±3.35 vs. 22.10±3.06 injured and uninjured, respectively)(p < .05). The ROC analysis determined the cut-off at ≤20 for both genders (sensitivity=.71, specificity=.81, for males; sensitivity=.67, specificity=.69, for females)(p<.05), suggesting moderate predictability for acute noncontact lower extremity injuries. Furthermore, significant positive correlations were found between the LEGS composite score and the multi-stage fitness test (r=.474, p=.003) in male subjects, suggesting a relationship between functional performance, aerobic capacity, and potential injury risk. Identifying individuals who are at greatest risk and prescribing corrective, neuromuscular, and cardiovascular exercise at the appropriate time during developmental stages for adolescent athletes may reduce sports-related injury risk.