Article

Step asymmetries during gait in persons after stroke can occur in
temporal or spatial domains. Prior studies have shown that split-belt locomotor
adaptation can temporarily mitigate these asymmetries.
OBJECTIVE: . We
investigated whether baseline gait asymmetries affected how patients adapt and
store new walking patterns. METHODS: Subjects with stroke and age-matched
controls were studied walking at a 2:1 speed ratio on the split-belt during
adaptation and assessed for retention of the learned pattern (the after-effect)
with both belts at the same speed. RESULTS: Those with stroke adapted more slowly
(P < .0001), though just as much as healthy older adults. During split-belt
walking, the participants with stroke adapted toward their baseline asymmetry
(eg, F = 14.02, P < .01 for step symmetry), regardless of whether the subsequent
after-effects improved or worsened their baseline step asymmetries. No
correlation was found between baseline spatial and temporal measures of asymmetry
(P = .38). Last, the initial spatial and temporal asymmetries predicted
after-effects independently of one another. The after-effects in the spatial
domain (ie, center of oscillation difference) are only predicted by center of
oscillation difference baseline (F = 15.3, P = .001), while all other parameters
were nonsignificant (all Ps > .17). Temporal coordination (ie, phasing)
after-effects showed a significant effect only from phasing baseline (F = 26.92,
P < .001, all others P > .33). CONCLUSION: This work demonstrates that stroke
patients adapt toward their baseline temporal and spatial asymmetries of walking
independently of one another. We define how a given split-belt training session
would affect asymmetries in these domains, which must be considered when
developing rehabilitation interventions for stroke patients.

Langue : ANGLAIS