 A. Specific Aims The Specific Aims have not been modified from the original application. Our long-term goals are to determine the mechanisms by which female athletes become more susceptible to ACL injury and to develop interventions that address these mechanisms in order to reduce knee loads and ACL injury risk. The major goal of this proposal is to determine if decreased neuromuscular control of the trunk increases coronal plane knee load in high-risk groups of females. This overall objective of this application is to test the central hypotheses that lateral trunk motion increases knee load and that neuromuscular training that increases control of trunk motion will decrease knee abduction loading in females with moderate and high knee loads. Our rationale for this project is that its successful completion will provide a strong, evidence-based intervention that will effectively decrease ACL injury risk in high-risk female athletes. 