Protective movements during sideways falls from standing height.

To examine the effect of protective movements during sideways falls from standing height (i.e., from the standing position), a two-step study was performed. In the first step, 80 young male and female volunteers freely fell onto a sport-mat. All falls were recorded on videotape, and replayed to analyze movements in response to the falls. Several protective movements were observed; forward flexion and lateral flexion were observed with a particularly high frequency. In the second step, impact velocities of the head and hip were measured by a three-dimensional motion analyzer regarding three types of falls: stiff falls, forward flexion falls and lateral flexion falls. Both types of flexion reduced impact velocities of the head, but not those of the hip. The reduction of the impact velocity on the head correlated with the lowering of the height of the head from the floor.