Article

The extent to which the upper-limb flexor synergy constrains or
compensates for arm motor impairment during reaching is controversial. This
synergy can be quantified with a minimal marker set describing movements of the
arm-plane. Objectives To determine whether and how (a) upper-limb flexor synergy
in patients with chronic stroke contributes to reaching movements to different
arm workspace locations and (b) reaching deficits can be characterized by
arm-plane motion. Methods Sixteen post-stroke and 8 healthy control subjects made
unrestrained reaching movements to targets located in ipsilateral, central, and
contralateral arm workspaces. Arm-plane, arm, and trunk motion, and their
temporal and spatial linkages were analyzed. Results Individuals with
moderate/severe stroke used greater arm-plane movement and compensatory trunk
movement compared to those with mild stroke and control subjects. Arm-plane and
trunk movements were more temporally coupled in stroke compared with controls.
Reaching accuracy was related to different segment and joint combinations for
each target and group: arm-plane movement in controls and mild stroke subjects,
and trunk and elbow movements in moderate/severe stroke subjects. Arm-plane
movement increased with time since stroke and when combined with trunk rotation,
discriminated between different subject groups for reaching the central and
contralateral targets. Trunk movement and arm-plane angle during target reaches
predicted the subject group. Conclusions The upper-limb flexor synergy was used
adaptively for reaching accuracy by patients with mild, but not moderate/severe
stroke. The flexor synergy, as parameterized by the amount of arm-plane motion,
can be used by clinicians to identify levels of motor recovery in patients with
stroke.
CI - (c) The Author(s) 2015.

Langue : ANGLAIS