Stride variability in human gait: the effect of stride frequency and stride length

This study focused on spatial and temporal variability of the stride in human gait. We determined the role of stride frequency (F) and stride length (L) on those parameters. Eight healthy subjects walked on a treadmill using 25 different FL combinations (0.95 < L < 1.5 in, and 0.8 < F < 1.26 Hz). The results showed that spatial and temporal variabilities tend to increase in concert with respect to change in stride parameters. In addition, stride variability was found (1) to be minimal at F= I Hz; and (2) to increase with smaller L. During additional trials, subjects walked freely at various speeds. Although it is generally hypothesized that freely chosen behaviors are optimal in terms of variability, our data show that this is not always the case in human gait. (C) 2003 Elsevier Science B.V. All rights reserved.