Comparison of multimodal return-to-sport testing and force plate-based balance testing among anterior cruciate...

The purpose of our study was to identify force plate-derived balance metrics that were predictive of multimodal return-to-sport test findings in a sample of anterior cruciate ligament reconstruction patients.

We conducted a cross-sectional study of anterior cruciate ligament reconstruction patients who were at least 6 months postoperative. Subjects completed our multimodal Institutional RTS testing battery which included testing of hip and knee range of motion (ROM), isokinetic quadriceps strength, and core trunk muscle strength (Bunkie test), as well as balance testing on a force plate. Balance metrics predictive of Institutional RTS test findings for the involved leg were identified using multivariable regression with stepwise selection. Model significance was assessed at α = 0.002.

Sixteen subjects (7M, 9F) were enrolled in our study with a median age of 29 years (range 20-47). Multivariate multiscale entropy (MMSExyz) of the involved leg was predictive of knee flexion active ROM (P = .02) and Bunkie stabilizing test score (P = .03), MMSExyz of the uninvolved leg was predictive of Bunkie lateral and medial test scores (P = .02 and P = .02), and interlimb symmetry of MMSExyz was predictive of triple jump test score (P = .007). Interlimb symmetry of the COPx shift balance metric was predictive of hip internal rotation active and passive ROM (P = .008 and P = .03) and step-down test score (P = .004).

Force plate-based balance testing metrics are predictive of some return-to-sport test findings including knee flexion ROM and Bunkie test scores, but further analysis is needed to identify balance metrics predictive of quadriceps isokinetic testing and muscle flexibility testing results.