Article

Despite a large number of studies that have considered footstrike pattern,
relatively little is known about how runners alter their footstrike pattern with
running velocity. The purpose of this study was to determine how footstrike
pattern, defined by footstrike angle (FSA), is affected by running velocity in
recreational athletes. One hundred and two recreational athletes ran on a
treadmill at up to ten set velocities ranging from 2.2-6.1 ms(-1). Footstrike
angle (positive rearfoot strike, negative forefoot strike), as well as stride
frequency, normalised stride length, ground contact time and duty factor, were
obtained from sagittal plane high speed video captured at 240 Hz. A probabilistic
curve-clustering method was applied to the FSA data of all participants. The
curve-clustering analysis identified three distinct and approximately equally
sized groups of behaviour: (1) small/negative FSA throughout; (2) large positive
FSA at low velocities (</= 4 ms(-1)) transitioning to a smaller FSA at higher
velocities (>/= 5 ms(-1)); (3) large positive FSA throughout. As expected, stride
frequency was higher, while normalised stride length, ground contact time and
duty factor were all lower for Cluster 1 compared to Cluster 3 across all
velocities; Cluster 2 typically displayed intermediate values. These three
clusters of FSA - velocity behaviour, and in particular the two differing trends
observed in runners with a large positive FSAs at lower velocities, can provide a
novel and relevant means of grouping athletes for further assessment of their
running biomechanics.
CI - Copyright (c) 2014 Elsevier B.V. All rights reserved.

Langue : ANGLAIS