Valgus Plus Internal Rotation Moments Increase Anterior Cruciate Ligament Strain More Than Either Alone

Abstract

Combined knee valgus and internal rotation moments increases ACL strain more than either alone. The combination of a valgus and internal rotational moment at magnitudes that occurs in vivo during landing can cause ACL strains that may be high enough to cause ACL rupture. This predicted high ACL strain and the contact force location suggest that combined valgus and internal tibial rotational moments during single-leg landing are relevant to ACL injuries.