Strength & Conditioning

Document Type



The purpose of this study was to assess the change in lower limb joint kinetics associated with anterior cruciate ligament injury (ACL) risk in sidesteps with and without task constraints. Female athletes (n=21) performed pre-planned and unplanned sidesteps with and without task constraints to the trunk and the preparatory step. Statistical differences in negative peak joint power for the hip, knee and ankle during the execution step, the entry velocity and the sidestep angle between the constrained and unconstrained sidesteps were determined with a linear mixed model. The entry velocity decreased for all unplanned sidesteps compared to pre-planned sidesteps. Trunk constraints increased knee joint loading in pre-planned sidesteps (-24.51 ± 11.27 W·kg-1) compared to unconstrained unplanned sidesteps (-17.69 ± 8.58 W·kg-1). Understanding how constraints can alter the magnitude of lower-body joint loading can help design effective drills to overload single-joint capacities.