Does A History Of Lower Extremity Injury Impact Female Athlete Jump Landing Performance Metrics?

Reaction time, jump height, reactive strength index, and vertical stiffness during jumping provide key insights into performance. Lower extremity injury history influences movement biomechanics but little is known about how this history impacts performance metrics. Examining these metrics following injury will elucidate if an injury leads to persistent negative performance. PURPOSE: To determine whether a history of lower extremity musculoskeletal injury detrimentally impacts jump landing performance metrics. METHODS: Division I female athletes (63 without lower extremity injury history [age: 19.3 ± 1.4 yr; height: 170.3 ± 8.6 cm; mass: 66.0 ± 9.6 kg], 56 with self-reported lower extremity injury history [age: 18.8 ± 1.2 yr; height: 170.6 ± 8.2 cm; mass: 65.4 ± 7.9 kg]) started on a 30 cm box. A green light cued the athletes to jump. Immediately upon seeing the light, athletes jumped forward with both feet, landed with one foot on each force plate, and then immediately performed a maximum vertical jump. We used independent t-tests (Hedges g effect size) and Mann-Whitney U (r effect size) tests for comparisons. Outcomes included reaction time (s), jump height (m), reactive strength index, and peak vertical stiffness (Nm-1·BW-1). RESULTS: Athletes with a history of lower extremity injury had slower reaction times compared to athletes without a history (p = 0.03, Hedges g = 0.41). There were no group differences for jump height (p = 0.20, r = 0.14), reactive strength index (p = 0.63, r = 0.05), or vertical stiffness (p = 0.07, r = 0.19). CONCLUSION: Reacting to visual cues in sports is critical to elite performance during competition. A history of lower extremity musculoskeletal injury may negatively impact an athlete’s performance despite clearance to return to sport. Clinicians and athletes should work together to improve reaction time following an injury.Figure 1.: Performance Distributions. A: Reaction Time. B: Reactive Strength Index. C: Vertical Stiffness. D. Jump Height