Residual Deficits in Reactive Strength After Anterior Cruciate Ligament Reconstruction in Soccer Players.

CONTEXT: Deficits in plyometric abilities are common after anterior cruciate ligament reconstruction (ACLR). Vertical rebound tasks may provide a targeted evaluation of knee function.

OBJECTIVE

To examine the utility of a vertical hop test for assessing function after ACLR and establishing factors associated with performance.

DESIGN

Cross-sectional study.

SETTING

Rehabilitation program.

PATIENTS OR OTHER

PARTICIPANTS

Soccer players with a history of ACLR (n = 73) and matched control individuals (n = 195).

MAIN OUTCOME MEASURE(S): The 10-second vertical hop test provided measures of jump height, the Reactive Strength Index (RSI), and asymmetry. We also examined possible predictors of hop performance, including single-legged vertical drop jump, isokinetic knee-extension strength, and the International Knee Documentation Committee questionnaire score.

RESULTS

Between-limbs differences were identified only for the ACLR group, and asymmetry scores increased in those with a history of ACLR (P < .001) compared with the control group. The single-legged vertical drop jump, RSI, and knee-extension torque were significant predictors of 10-second hop height (R2 = 20.1%) and RSI (R2 = 47.1%).

CONCLUSIONS

Vertical hop deficits were present after ACLR, even after participants completed a comprehensive rehabilitation program. This may have been due to reduced knee-extension and reactive strength. Vertical hop tests warrant inclusion as part of the return-to-sport test battery.