Normalized speed, not age, characterizes ground reaction force patterns in5-to 12-year-old children walking at self-selected speeds

Twenty-six healthy 5-year-old children were enrolled in a 7-year longitudin al study to examine the importance of age and speed in the characterization of ground reaction forces. One thousand forty gait trials of children walk ing at self-selected speeds were examined on the basis of age and normalize d speed [speed/(height x g)1/2]. Results, presented as discrete peak and tr ough values and as continuous trace plots over the stance phase, indicated that there was little change in ground reaction forces with age, but there were significant changes in vertical force and anterior-posterior force val ues with normalized speed. The ground reaction force patterns in these chil dren were characterized predominantly by normalized speed of progression an d not age. The clinical relevance of these findings is that normalized spee d of walking, rather than age, should be considered when comparing normal w ith pathological gait.