Table 1.

Comparison between the initial COM horizontal velocities necessary to prevent backward balance loss for walking and for standing derived from the current study as well as the published results (in parenthesis) (Pai and Patton, 1997) at two initial COM positions

xCOM	${\stackrel{.}{x}}_{\mathrm{COM}}$
	(a) Walking	(b) Standing	a/b (%)
−0.50	0.150	0.109 (0.094*)	138
−1.00	0.258	0.190 (0.186*)	136

The COM position and forward velocity are dimensionless variables expressed as a fraction of l_BOS and $\sqrt{g\times h}$, respectively, where l_BOS represents the length of the foot, g is the gravity constant, and h is the body height.