Abstract
Muscle fatigue induced by a previous sustained contraction temporarily decreases the motor output, transiently worsening motor performance. Whether muscle fatigue alters motor performance also in dystonia - a disorder whose main pathophysiological abnormality is motor overflow - remains unknown. To assess the effects of muscle fatigue in patients with focal occupational upper limb dystonia, we studied the effect of a previous maximum fatiguing voluntary contraction on motor performance in 10 musicians with focal occupational dystonia, in 3 musicians with hand motor impairment due to non-dystonic disorders, and in 5 normal musicians. The fatiguing task consisted of grasping a spring handgrip as long as possible until the task failed. In dystonic musicians, a fatiguing contraction significantly improved motor performance. The improvement lasted less than 5 minutes and appeared only after fatigue of the affected upper limb. In contrast, in musicians with non-dystonic motor impairment, motor performance remained unchanged or worsened, and normal musician performance consistently worsened.
Original language | English |
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Pages (from-to) | 1143-1147 |
Number of pages | 5 |
Journal | Movement Disorders |
Volume | 16 |
Issue number | 6 |
DOIs | |
Publication status | Published - Nov 2001 |
Keywords
- Dystonia
- Motor fatigue
- Musician's cramp
- Occupational dystonia
ASJC Scopus subject areas
- Clinical Neurology
- Neuroscience(all)