Effect of hamstrings muscle action on stability of the ACL-deficient knee in isokinetic extension exercise

Abstract

Objective. To quantify the effect of hamstrings muscle action on stability of the anterior cruciate ligament deficient knee during isokinetic exercise at various speeds. Design. Mathematical modeling and forward-dynamics computer simulation were used to study the interactions between knee-extension speed, hamstrings co-contraction activity, and anterior tibial translation in the intact and anterior cruciate deficient knee. Background. There is much experimental evidence available to believe that hamstrings co-contraction can reduce anterior tibial translation in the anterior cruciate deficient knee. Little is known, however, about the level of hamstrings activation needed to keep anterior ti..