Variabilities in orthogonal ground reaction forces during self-paced walking on the dual belt treadmill

In order to study dynamic balance of stance phase during self-paced walking, variations in orthogonal ground reaction forces (GRF) were examined by using force-plate installed dual belt treadmill. As walking speed increased, standard deviations (SDs) in GRFs tended to be higher both at the beginning and ending in double support phase (DSP) especially in Fvertical and Fa-p. In DSP, control of breaking action in leading leg as well as acceleration action in trailing leg constraint for stable walking at faster speed. Unstable dynamic balance might be caused especially at the beginning and ending phases in DSP during self-paced normal fast walking.