Quadriceps and Hamstrings Peak Torque Ratio Changes in Persons With Chronic Anterior Cruciate Ligament Deficiency

Abstract

Quadriceps and hamstrings peak torque values were significantly decreased in ACL deficient compared with the uninvolved limb. Eccentric muscle activity was affected to a greater degree than concentric muscle activity in the quadriceps muscle after ACL injury. The eccentric hamstrings/concentric quadriceps ratios were similar in ACL deficient and normal limbs, indicating that muscular co-ordination strategies may have been altered to maintain normal limb activity despite the strength losses particularly evident in quadriceps muscle function.