Task-dependent deficits during object release in Parkinson's disease.
The present study examined fingertip forces during the replacement and release of an instrumented object on a table in eight subjects with Parkinson's disease (PD) both off and on medication and eight age-matched control subjects. Subjects performed the task at (1) their preferred speeds and (2) as fast as possible. During performance of the task at preferred speed, the duration of object replacement, the rate, and duration of force decrease following table contact for PD subjects were similar to that observed in the control subjects and were unaffected by medication. In contrast, the rates were significantly lower and durations longer in the PD subjects when the task was performed as fast as possible irrespective of medication. A similar result was obtained when subjects were asked to release their pinch force from predefined force levels while the object was fixed to the table surface. These results emphasize the importance of considering task requirements in order to delineate the specific task parameters associated with the movement impairments in Parkinson's disease.
Teachers College, Columbia University, 525 West 120th Street, New York, New York, 10027, USA.
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Gordon
D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D005260:Female; D005385:Fingers; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D011597:Psychomotor Performance; D011930:Reaction Time; D012016:Reference Values
D000978:Antiparkinson Agents