Wave pattern of ground reaction force of growing children.

We studied the free gait of children by analyzing the wave pattern of the ground reaction force (GRF) and measuring time and distance parameters using large force plates. Two hundred and forty-one normal children, age 4-10 years, were included. Normalized waves of each subject were obtained by computer. Waves are composed of fore-aft, medial-lateral, and vertical components. We took nine specific points on these waves and analyzed the values of specific points and time and distance measurements. We found significant changes of these parameters up to approximately 8 years of age. These findings serve as GRF control data and are useful in evaluating pathological gaits.