Reactive Strength as a Metric for Informing Return-to-Sport Decisions: A Case-Control Study.

Abstract

Current return-to-sport decisions are primarily based on elapsed time since surgery or injury and strength measures. Given data that show rates of successful return to competitive sport at around 55%, there is strong rationale for adopting tools that will better inform return to sport decisions. The authors' objective was to assess reactive strength as a metric for informing return-to-sport decisions. Case-control design. Fifteen elite athletes from national sports teams (23 [6.0]y) in the final phase of their return-to-sport protocol following a unilateral knee injury and 16 age-matched control athletes (22 [4.6]y) performed a unilateral isometric strength test and 24-cm drop jump test. Pairwise comparisons were used to determine differences between legs within groups and differences in interleg asymmetry between groups. Strength measures did not distinguish the control from the rehabilitation group; however, clear differences in the degree of asymmetry were apparent between the control and rehabilitation groups for contact time (Cohen d = 0.56; -0.14 to 1.27; 8.2%; P = .113), flight time (d = 1.10; 0.44 to 1.76; 16.0%; P = .002), and reactive strength index (d = 1.27; 0.50 to 2.04; 22.4%; P = .002). Reactive strength data provide insight into functional deficits that persist into the final phase of a return-to-sport protocol. The authors' findings support the use of dynamic assessment tools to inform return-to-sport decisions to limit potential for reinjury.