Article

Based on the windlass mechanism theory of Hicks, the medial
longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot
lengthening is expected. However, changes in foot length during gait and the
influence of walking speed has not been investigated yet. METHODS: The foot
length and MLA angle of 34 healthy subjects (18 males, 16 females) at 3
velocities (preferred, low (preferred -0.4 m/s) and fast (preferred +0.4 m/s)
speed were investigated with a 3D motion analysis system (VICON((R))). The MLA
angle was calculated as the angle between the second metatarsal head, the
navicular tuberculum and the heel in the local sagittal plane. Foot length was
calculated as the distance between the marker at the heel and the 2nd metatarsal
head. A General Linear Model for repeated measures was used to indicate
significant differences in MLA angle and foot length between different walking
speeds. RESULTS: The foot lengthened during the weight acceptance phase of gait
and shortened during propulsion. With increased walking speed, the foot elongated
less after heel strike and shortened more during push off. The MLA angle and foot
length curve were similar, except between 50% and 80% of the stance phase in
which the MLA increases whereas the foot length showed a slight decrease.
CONCLUSION: Foot length seems to represent the Hicks mechanism in the foot and
the ability of the foot to bear weight. At higher speeds, the foot becomes
relatively stiffer, presumably to act as a lever arm to provide extra propulsion.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS