Article

OBJECTIVE: To examine the velocity-dependent change in medial gastrocnemius (MG)
activity during the stance phase of gait in patients with moderate to severe
resting hypertonia after stroke or traumatic brain injury (TBI). DESIGN: Cohort
study. SETTING: Motion analysis laboratory in a tertiary-care rehabilitation
hospital. PARTICIPANTS: Convenience sample of patients with chronic TBI and
stroke (n=11 each), and age- and sex-matched healthy controls (n=22).
MAIN OUTCOME MEASURES: Frequency and gain
(steepness) of positive (>0) and significant positive (>0 and goodness of fit
P</=.05) electromyogram-lengthening velocity (EMG-LV) linear regression slope in
MG during the stance phase of gait. RESULTS: Positive and significant positive
slopes were found significantly more often on the more affected (MA) than less
affected (LA) side in patients with TBI but not stroke. Both the frequencies of
positive and significant positive slopes on the MA side in patients with TBI were
also significantly higher than in controls. However, neither the gain of positive
nor significant positive EMG-LV slope was different between the MA and LA sides
or in comparison with controls. Positive slope parameters were not related to
Ashworth score on the MA side. CONCLUSIONS: The frequency and gain of positive
EMG-lengthening slope did not effectively differentiate patients from controls,
nor were they related to the resting muscle hypertonia. Motor output during MG
lengthening in the stance phase of gait is apparently not exaggerated or related
to resting hypertonia in patients with chronic TBI and stroke. Thus, changes in
gait during stance cannot be ascribed to increased stretch reflex activity in MG
muscle after acquired brain injury.
CI - Copyright (c) 2012 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS