Sport-dependent variations in arm position during single-limb landing influence knee loading: implications for anterior cruciate ligament injury.

Abstract

Increased valgus loading at the knee has been previously identified as a possible risk factor for noncontact anterior cruciate ligament injuries, which are common in sports. Arm position variation may affect risk of injury by altering valgus knee loading. Sport-dependent variations in arm position increase valgus loading of the knee during run-to-cut maneuvers. Controlled laboratory study. Eleven subjects performed a sidestep cutting maneuver, first with no arm constraints and then with 3 sports-related arm positions in random order (holding a lacrosse stick, holding a football on the plant side, and holding a football on the cut side). The analysis focused on the knee valgus moment relative to the arm positions during the landing phase of the activity. Arm position significantly influenced the valgus moment with an increase in the lacrosse trials and in the plant-side football trials but not in the cut-side football trials (alpha = .05). Constraining the plant-side arm results in increased valgus loading at the knee during run-to-cut maneuvers, which suggests the possibility of greater risk of anterior cruciate ligament injury during these conditions. These results suggest that training methods that consider arm position as a risk factor could help reduce the risk of anterior cruciate ligament noncontact injury.