Article

The generation of whole-body angular momentum is essential in many locomotor
tasks and must be regulated in order to maintain dynamic balance. However,
angular momentum has not been investigated during stair walking, which is an
activity that presents a biomechanical challenge for balance-impaired
populations. We investigated three-dimensional whole-body angular momentum during
stair ascent and descent and compared it to level walking. Three-dimensional
body-segment kinematic and ground reaction force (GRF) data were collected from
30 healthy subjects. Angular momentum was calculated using a 13-segment
whole-body model. GRFs, external moment arms and net joint moments were used to
interpret the angular momentum results. The range of frontal plane angular
momentum was greater for stair ascent relative to level walking. In the
transverse and sagittal planes, the range of angular momentum was smaller in
stair ascent and descent relative to level walking. Significant differences were
also found in the ground reaction forces, external moment arms and net joint
moments. The sagittal plane angular momentum results suggest that individuals
alter angular momentum to effectively counteract potential trips during stair
ascent, and reduce the range of angular momentum to avoid falling forward during
stair descent. Further, significant differences in joint moments suggest
potential neuromuscular mechanisms that account for the differences in angular
momentum between walking conditions. These results provide a baseline for
comparison to impaired populations that have difficulty maintaining dynamic
balance, particularly during stair ascent and descent.
CI - Copyright (c) 2014 Elsevier B.V. All rights reserved.

Langue : ANGLAIS