Investigation of Force Plate Jump Testing Metrics Relevant to Return to Play Decision Making in Basketball Athletes After Anterior Cruciate Ligament Reconstruction.

Abstract

Force plate vertical jump testing can identify persistent lower limb asymmetries after anterior cruciate ligament reconstruction (ACLR). Unfortunately, there is no consensus on which vertical jump task, nor the hundreds of available metric assessment combinations that are relevant to basketball athletes after ACLR. # Purpose The purpose of this study was to examine the jump performances of high school and collegiate male basketball athletes in the final stages of ACLR rehabilitation to 1) establish referenceable between-limb symmetry scores, and 2) identify metrics that best detect between-limb asymmetry during common vertical jump tasks. # Study Design Retrospective cohort examination # Methods Forty-nine male high school and collegiate basketball athletes who underwent primary ACLR were examined using a dual force plate system in the final stages rehabilitation. Participants were subdivided into two groups: athletes who exhibited above or below 90% isokinetic quadriceps peak torque limb symmetry index (LSI). Select jump metrics were collected from three jumping tasks: double-leg countermovement jump (DL-CMJ), single-leg countermovement jump (SL-CMJ), and single-leg repeat hop (SL-RH). Referenceable LSI jump scores were reported using descriptive analysis and compared between the two groups using independent samples t-tests. # Results Significant differences in LSI between the two groups were identified (p< 0.05) during the DL-CMJ: eccentric rate of force development (MD= -22.6), concentric impulse (MD= -22.4), concentric impulse 100ms (MD= -24.0), contact time (MD= -.43), and peak take-off force (MD= -12.7), and during the SL-RH: jump height (MD= -12.4) and flight time:contact time (MD= 13.3). No significant differences were found during SL-CMJ testing. # Conclusions In the final phases of ACLR rehabilitation, basketball athletes who exhibit quadriceps strength asymmetry also demonstrated greater asymmetry during double-leg and single-leg reactive jumping tasks but not during single-leg countermovement jumps suggesting the importance of a battery of jump tests to ensure adequate restoration of physical qualities required for the sport. # Level of Evidence Level 3.