Anterior cruciate ligament (ACL) is the most commonly injured knee ligament in sports-related activities, especially in pivoting sports. Considering that the knee is free to flex/extend but has much more limited motions about the off-axes (tibial rotation and valgus/varus), ACL injuries are often associated with excessive off-axis loadings. A pivoting/sliding mechanism combined with sagittal plane movement/exercise is described as a diagnostic tool to evaluate off-axis neuromechanical and anatomical risk factors of noncontact ACL injuries. The pivoting/sliding mechanism is also described as an intervention tool for off-axis training, possibly based on the diagnosis, to reduce the incidence of ACL injuries. Training outcome can also be evaluated using the pivoting/sliding mechanism. In general, the pivoting/sliding mechanism can be used with many sagittal plane exercise machines and used to improve off-axis control of the lower limbs and reduce lower limb injuries.