<bold>Purpose.</bold> In this study, the effect of added weights on the various force and time related characteristics of vertical ground reaction force (VGRF) during the last five steps prior to walk-to-run transition was studied. <bold>Basic procedures.</bold> Experimental set up consisted of a force platform embedded treadmill. Sixteen college students performed experimental trials by carrying 0%, 10%, 20% and 30% of their body weight. During each trial, after walking for about 30 seconds the speed of the treadmill was increased manually at a rate of 0.089 m/s/s (0.2 miles/hour) until the participant started running. <bold>Main findings.</bold> A significant interaction (weights × steps) was observed for the first peak of VGRF. The trough, second peak, impulse, and rate of force development of VGRF increased with added weights. During the last five walking steps, most of VGRF parameters changed in a nonlinear fashion. <bold>Conclusions.</bold> Based on the behavior of VGRF parameters and manually recorded preferred transition speed values, we argue that the added weights would reduce the walk-to-run transition speed. We further speculate that a combination of transition determinants actively participate in the reorganization process during the last five walking steps, prompting the gait transition.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.