Article

Impaired motor control of the upper extremity after stroke may be
related to lost sensory, motor, and integrative functions of the brain.
Artificial activation of sensory afferents might improve control of movement by
adding excitatory drive to sensorimotor control structures. The authors evaluated
the effect of wrist tendon vibration (TV) on paretic upper-arm stability during
point-to-point planar movements. METHODS: TV (70 Hz) was applied to the forearm
wrist musculature of 10 hemiparetic stroke patients as they made center-out
planar arm movements. End-point stability, muscle activity, and grip pressure
were compared as patients stabilized at the target position for trials completed
before, during, and after the application of the vibratory stimulus. RESULTS:
Prior to vibration, hand position fluctuated as participants attempted to
maintain the hand at the target after movement termination. TV improved arm
stability, as evidenced by decreased magnitude of hand tangential velocity at the
target. Improved stability was accompanied by a decrease in muscle activity
throughout the arm as well as a mean decrease in grip pressure. CONCLUSIONS:
These results suggest that vibratory stimulation of the distal wrist musculature
enhances stability of the proximal arm and can be studied further as a mode for
improving end-point stability during reaching in hemiparetic patients.

Langue : ANGLAIS