Comparison of Different Functional Tests for Leg Power and Normative Bilateral Asymmetry Index in Healthy Collegiate Athletes

Abstract

Background Bilateral leg power is being increasingly investigated as a proxy for the recovery of muscle performance after injury. Functional tests like the single leg hop for distance (SLHD) and single leg vertical jump (SLVJ) are often used to determine symmetry and return to play (RTP) readiness. As an injury predictor, leg power is accurately measured with the Keiser Air420 seated leg press. Purpose To measure and analyze lower leg asymmetry in healthy collegiate athletes across each test battery. Methods Eighty-eight healthy student-athletes (44 males, 44 females) across 14 varsity teams at Wake Forest University performed the SLHD, SLVJ, and the Keiser. Horizontal and vertical displacement were measured via the SLHD and SLVJ, respectively. Peak power was recorded via the Keiser Air420 leg press. Pearson correlations and repeated measures ANOVA were used to calculate associations and compare bilateral asymmetry indices (BAI) and raw scores. Results There was a significant effect on each test’s raw BAI ( P < 0.01). The mean absolute BAI were 5.42 ± 4.9%, 6.64 ± 4.9% and 5.36 ± 4.7% for the SLHD, SLVJ and Keiser, respectively. The SLVJ and Keiser (dominant leg r = 0.832, nondominant leg r = 0.826) were more highly correlated than the SLHD and Keiser (dominant leg r = 0.645, nondominant leg r = 0.687), all of which were statistically significant ( P < 0.01). Conclusion At the 90th percentile, healthy collegiate athletes attained <15% BAI. We recommend the implementation of a battery of tests to determine normative lower limb asymmetry. A battery of functional tests may present different asymmetry indices as opposed the 10% reference asymmetry.

A Compound Hop Index for Assessing Soccer Players’ Performance

“…Then, the participants performed a battery of three single-leg hop tests, including, consecutively, a single hop for the distance test, a triple hop for the distance test, and the six-meter timed hop test [ 16 , 18 , 31 , 32 , 33 ]. The test order was randomly assigned to each participant.…”

Correlations Between Preseason Functional Test Scores and Game Performance in Female Collegiate Volleyball Players

“…First, SLJ and SLH measures can be used by coaches to evaluate aspects of an athlete's lower extremity power. 1,2,[31][32][33][34][35][36] Many smaller universities (i.e., non-Division I institutions) lack expensive equipment (e.g., isokinetic machines) to test their athletes; the SLJ and SLH tests may be used as clinical correlates for quantifying lower extremity power. 1,2,[31][32][33][34][35][36] There were several low to moderate level positive correlations between jump or hop performance and game statistics (Table 2).…”

“…1,2,[31][32][33][34][35][36] Many smaller universities (i.e., non-Division I institutions) lack expensive equipment (e.g., isokinetic machines) to test their athletes; the SLJ and SLH tests may be used as clinical correlates for quantifying lower extremity power. 1,2,[31][32][33][34][35][36] There were several low to moderate level positive correlations between jump or hop performance and game statistics (Table 2). The jump and hop tests appear to have the greatest value when evaluating VB athletes per position (Table 3a).…”