Isolating the particular joints/limb segments associated with knee adductor moment variability may provide clinically important data that could help to identify strategies to reduce medial tibiofemoral joint load. The aim of this study was to examine whether or not foot and thigh rotation during human locomotion are significant determinants of knee adductor moment variability. Three-dimensional gait analyses were performed on 32 healthy adult women (mean age 54+/-12 years, mean BMI 25+/-4 kg m(-2)) with radiologically normal knees. The relationships between foot rotation, thigh rotation and the external knee adduction moment were examined during early and late-stance phases of the gait cycle. The degree of foot rotation correlated significantly with the magnitude of the peak knee adduction moment during late stance (r=0.40, p=0.024). No significant associations were apparent between thigh rotation and the peak knee adduction moment. The association between foot rotation and the knee adduction moment in this study suggests that women who walk with external rotation at the foot reduce their knee adduction moment during late stance. This result implies that changes in foot kinematics can modify the medial tibiofemoral load during gait, which may be important in the prevention and management of knee osteoarthritis.