Dynamic multi and single joint strength and vertical jump performance in amateur athletes who have returned to sport following anterior cruciate ligament reconstruction.

BACKGROUND

The aim of this study is to examine relative five-repetition maximum (RM) box squat, rear-foot elevated split squat (RFESS), leg extension strength and vertical jump scores in amateur athletes who have returned to sport following anterior cruciate ligament (ACL) reconstruction.

METHODS

Overall, 53 amateur athletes completed a strength and vertical jump assessment including 5RM box squat, RFESS, Leg Extension, countermovement jump (CMJ), single leg (SL) CMJ and SL drop jump (DJ).

RESULTS

Relative 5RM values of 1.16, 0.6 and 0.65 were found for box squat, RFESS and leg extension respectively. Significant main effects of limb were observed across most outcomes, with the ACL-reconstructed limb showing lower strength and jump performance. Males outperformed females on all strength and jump metrics. A main effect of graft type was found for leg extension strength, but post-hoc comparisons were not significant. Time from surgery did not moderate the effects of limb, gender, or graft type, except for one interaction with eccentric deceleration impulse.

CONCLUSIONS

Single joint strength and vertical jump scores were lower in the ACL reconstructed limb in comparison to the uninvolved limb, whereas no differences were found in RFESS. Females showed lower relative scores in all tests, whereas no difference was found according to graft type. Time from surgery did not moderate the effects of limb, gender and graft type on strength and vertical jump scores, except for SLCMJ eccentric deceleration impulse.