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 reconstruction using autogenous middle third of the patellar tendon. All patients had good subjective and objective results at the time of analysis. Differences in gait between subjects and controls persisted up to 12 months after surgery. Specifically, subjects with anterior cruciate 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 reconstruction, there is a tendency toward gait normalization, and a quadriceps avoidance mechanism is no longer present.