Motor control impairment of the contralateral wrist in patients with unilateral chronic wrist pain.
OBJECTIVE
Assessment of the quality of fine motor control in patients with unilateral chronic wrist pain seldom focuses on the possibility that control of movements is effector independent at the cerebral level. This mechanism may be involved in an impairment of motor function in the unaffected wrist. We studied the possible motor impairment in the unaffected wrist in patients with chronic wrist pain.


METHODS
Eighteen patients with chronic wrist pain in their dominant hand and 20 healthy controls performed, using their nondominant hand, back-and-forth, left-to-right stroke patterns with a pen on a digital writing tablet connected to a computer. Fluency of movement, defined as the number of zero-crossings of the acceleration curve (pZC), average stroke size, and average velocity were calculated.


RESULTS
The controls moved significantly more fluently than the patients (pZC, 0.26+/-0.07 for controls and 0.46+/-0.20 for patients; P < 0.001), suggesting that long-term afferent disturbances may compromise cerebral motor control mechanisms.


CONCLUSIONS
This result is in accordance with the view that chronic pain complaints may be maintained by persistently abnormal cerebral motor control. This finding opens a new perspective on the understanding and treatment of chronic wrist pain.
Smeulders
Mark J C
MJ
Department of Plastic, Reconstructive, and Hand Surgery, Academic Medical Center, Amsterdam, The Netherlands.
Kreulen
Michiel
M
Hage
J Joris
JJ
Ritt
Marco J P F
MJ
Mulder
Theo
T
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D002908:Chronic Disease; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006236:Handwriting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D016472:Motor Neuron Disease / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D014953:Wrist / Q000503:physiopathology*