Article

Symmetrical limb movement requires complex muscle coordination patterns.
Consequently, coordination impairments lead to asymmetric gait patterns, as often
seen in stroke subjects. Split-belt walking has previously been used to induce
limping-like walking in able-bodied adults. The goal of this study is to analyze
how muscle coordination patterns that control the centre of mass are modulated
during an asymmetric gait pattern imposed on healthy subjects. These modulations
can be uniquely related to the biomechanics of limping as no pathology is
present. Forward simulations of limping-like walking (split-belt) and
corresponding symmetric conditions (tied-belt) were generated for twelve healthy
subjects. Our results show that the differences between 'fast' and 'slow' leg
contributions during split-belt walking are not attributable to simple
differences in speed between the belts, because most split-belt muscle
contributions differ from tied-belt walking. Different types of modulations,
inducing increased, decreased or even reversed asymmetry (e.g. plantarflexors,
biceps femoris short head, and quadriceps respectively), underlie limping-like
walking in healthy subjects. In general, these patterns present large
similarities with adaptations previously described in hemiplegic subjects.
However, differences were found with gluteus medius and biceps femoris short head
contributions in hemiplegic subjects, suggesting that the latter are not just
related to limping, but to concomitant deficits.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS