Changing sidestep cutting technique reduces knee valgus loading.

BACKGROUND Common lower limb postures have been found when noncontact anterior cruciate ligament (ACL) injuries occur during sidestep cutting tasks. These same postures have been linked to knee loadings known to stress the ACL. HYPOTHESIS Whole body technique modification would reduce knee loading. STUDY DESIGN Controlled laboratory study. METHODS Experienced team sport athletes were recruited for whole body sidestep cutting technique modification. Before and after a 6-week technique modification training, participants performed sidestep cutting tasks while ground-reaction force and motion data were collected. A kinematic and inverse dynamics model was used to calculate 3-dimensional knee loading during sidestep cutting. RESULTS At initial foot contact, the participants placed their stance foot closer to the body's midline and held their torso more upright, in line with the aims of the technique modification training. This was accompanied by significantly lower peak valgus moments in the weight acceptance phase of stance. Both postural changes were correlated with the change in peak valgus moment. CONCLUSION Whole body sidestep cutting technique modification resulted in reduced knee loading. CLINICAL RELEVANCE Implementation of whole body technique modification may produce effective ACL injury prevention programs in sports involving sidestep cutting.