Abstract
Background.
Kinematic abundance permits using different movement patterns for task
completion. Individuals poststroke may take advantage of abundance by
using compensatory trunk displacement to overcome upper limb (UL)
movement deficits. However, movement adaptation in tasks requiring
specific intersegment coordination may remain limited.
Objective.
We tested movement adaptation in both arms of individuals with chronic
stroke (n = 16) and nondominant arms of controls (n = 12) using 2
no-vision reaching tasks involving trunk movement (40 trials/arm).
Methods.
In the “stationary hand task” (SHT), subjects maintained the hand
motionless over a target while leaning the trunk forward. In the
“reaching hand task” (RHT), subjects reached to the target while leaning
forward. For both tasks, trunk movement was unexpectedly blocked in 40%
of trials to assess the influence of trunk movement on adaptive arm
positioning or reaching. UL sensorimotor impairment, activity, and
sitting balance were assessed in the stroke group. The primary outcome
measure for SHT was gain (g), defined as the extent to which
trunk displacement contributing to hand motion was offset by appropriate
changes in UL movements (g = 1: complete compensation) and endpoint deviation for RHT.
Results.
Individuals poststroke had lower gains and greater endpoint deviation
using the more-affected compared with less-affected UL and controls.
Those with less sensorimotor impairment, greater activity levels, and
better sitting balance had higher gains and smaller endpoint deviations.
Lower gains were associated with diminished UL adaptability.
Conclusions.
Tests of condition-specific adaptability of interjoint coordination may
be used to measure UL adaptability and changes in adaptability with
treatment.
No comments:
Post a Comment