Anterior-cruciate-ligament reconstruction does not alter the knee-extensor moment arm during gait

Abstract

Background: The ability of the quadriceps muscles to extend the knee depends on the moment arm of the knee-extensor mechanism, which is described by the moment arm of the patellar tendon at the knee. The knee-extensor moment may be altered by a change in quadriceps force, a change in the patellar tendon moment arm (PTMA), or both. A change in quadriceps muscle strength after anterior-cruciate-ligament-reconstruction (ACLR) surgery is well documented, however, there is limited knowledge about how this procedure affects the PTMA. Research question: Does ACLR surgery alter the moment arm of the knee-extensor mechanism during gait? Methods: We measured the PTMA in both the ACLR knee and the unin..