Article

Musculoskeletal simulations have been used to explore compensatory strategies,
but have focused on responses to simulated atrophy in a single muscle or muscle
group. In a population such as stroke, however, impairments are seen in muscle
activation across multiple muscle groups. The objective of this study was to
identify available compensatory strategies for muscle weakness during gait by
simulating activation deficits in multiple muscle groups. Three dimensional
dynamics simulations were created from 10 healthy subjects (48.8 +/- 13.3 years,
self-selected speed 1.28 +/- 0.17 m/s) and constraints were set on the activation
capacity of the plantar flexor, dorsiflexor, and hamstrings muscle groups to
simulate activation impairme nts seen post-stroke. When the muscle groups are
impaired individually, the model requires that the plantar flexor, dorsiflexor,
and hamstrings muscle groups are activated to at least 55%, 64%, and 18%,
respectively, to recreate the subjects' normal gait pattern. The models were
unable to recreate the normal gait pattern with simultaneous impairment of all
three muscle groups. Other muscle groups are unable to assist the dorsiflexor
muscles during early swing, which suggests that rehabilitation or assistive
devices may be required to correct foot drop. By identifying how muscles can
interact, clinicians may be able to develop specific strategies for using gait
retraining and orthotic assistance to best address an individual's needs.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS