Influence of speed variation and age on ground reaction forces and stride parameters of children's normal gait.

The aim of this study was to assess the influence of both age and speed on ground reaction forces and temporal parameters during normal gait in children. Fifteen children aged 4-6 years (group 1), 16 aged 6-8 years (group 2), and 16 aged 8-10 years (group 3) walked at 2.7 km/h, 3.6 km/h, and 4.5 km/h on a treadmill. For each child thirty successive steps were recorded. The influence of speed and age on normalized gait parameters was examined with two-way analysis of variance. The first vertical peak force (Fz1) and all the antero-posterior forces of group 1 were higher than those of the other groups for the three speeds. The minimum vertical force (Fz2), the second vertical peak force (Fz3), and the duration of stride and stance were significantly higher in groups 2 and 3. For all the groups, Fz1 and all the antero-posterior forces increased with the speed while Fz2, stride, stance, and double-stance duration decreased. Fz3 was not influenced by speed variation. The results of this study show that age and walking speed influence ground reaction forces and stride time parameters in 4- to 10-year-old children.