Return of normal gait patterns after anterior cruciate ligament reconstruction

Individuals with anterior cruciate ligament deficiency typically do not have quadriceps activity during stance. This aberrant pattern has been termed "quadriceps avoidance" gait. We performed gait analysis during walking on 10 normal controls and 10 subjects 8 to 12 months after they had anterior cruciate ligament recon struction using autogenous middle third of the patellar tendon. All patients had good subjective and objective results at the time of analysis. Differences in gait be tween subjects and controls persisted up to 12 months after surgery. Specifically, subjects with anterior cru ciate ligament reconstructions demonstrated significant reductions in midstance knee flexion moments (P < 0.01) and tibially directed loading rates (P < 0.05) when compared with controls. However, the subjects had a net external flexion moment throughout most of the stance phase of gait, implying that quadriceps activity was present. After anterior cruciate ligament recon struction, there is a tendency toward gait normalization, and a quadriceps avoidance mechanism is no longer present.