Single-Leg Hop Test Performance and Isokinetic Knee Strength After Anterior Cruciate Ligament Reconstruction in Athletes

BACKGROUND: Isokinetic strength and hop tests are commonly used to assess athletes' readiness to return to sport after knee surgery. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate the results of single-leg hop and isokinetic knee strength testing in athletes who underwent anterior cruciate ligament reconstruction (ACLR) upon returning to sport participation as well as to study the correlation between these 2 test batteries. The secondary purpose was to compare the test results by graft type (patellar tendon or hamstring). It was hypothesized that there would be no statistically significant limb difference in either isokinetic knee strength or single-leg hop tests, that there would be a moderate to strong correlation between the 2 test batteries, and that there would be no significant difference between graft types. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: ). RESULTS: = -0.54). There was no statistically significant difference in hop test performance or isokinetic knee strength between graft types. CONCLUSION: The single-leg hop tests and isokinetic strength measurements were both useful for a bilateral comparison of knee functional performance and strength. Knee flexion strength deficits and flexion-to-extension ratios seemed to be correlated with single-leg hop test performance. There was no difference in postoperative hop test performance or knee strength according to graft type.