Force plate jump testing metrics are predictive of performance on a multimodal return to sport testing protocol among anterior cruciate ligament reconstruction patients at minimum six-month follow-up.

BACKGROUND

Force plate-based jump testing may serve as a potential alternative to traditional return to sport (RTS) testing batteries. The purpose of our study was to identify force plate jump metrics that were predictive of RTS test findings in patients who were at least six months postoperative following anterior cruciate ligament reconstruction (ACLR).

METHODS

We conducted a cross-sectional study of patients who underwent ACLR at our center and were at least six months postoperative. Subjects completed a multimodal Institutional RTS (IRTS) testing battery which included range of motion (ROM) testing and isokinetic quadriceps strength testing. Subjects also completed a countermovement jump testing protocol on a commercially-available force plate. Jump metrics predictive of IRTS test findings were identified using multivariable linear and logistic regression with stepwise selection. Model significance was assessed at α=0.002.

RESULTS

Sixteen patients (7M, 9F) were enrolled in our study with median age of 29 years (range 20-47). Relative concentric impulse was positively predictive of knee flexion active ROM (β=7.07, P=0.01) and passive ROM (β=9.79, P=0.003). Maximum power was positively predictive of quadriceps strength at 60 deg/s (β=3.27, P<0.001) and 180 deg/s (β=2.46, P<0.001). Center-of-pressure (COP) shift acceleration along the force plate X-axis was negatively predictive of Bunkie lateral test score (β=-945, P<0.001) and medial test score (β=-839, P=0.03).

CONCLUSIONS

Force plate-derived vertical jump testing metrics are predictive of certain components of a multimodal RTS physical assessment for ACLR patients, including knee flexion ROM, quadriceps strength on isokinetic testing, and Bunkie Test performance.