title: Skilled hand dexterity in Parkinson's disease: effects of adding a concurrent task.
abstract: OBJECTIVE
  To compare the performance of people with Parkinson's disease (PD) and unimpaired participants on a timed dexterity task and to examine the effects of adding a secondary task.
  
  
  METHODS
  A repeated measures analysis of performance for the 2 groups under unitask and dual-task conditions.
  
  
  METHODS
  All tests were conducted in a human movement laboratory.
  
  
  METHODS
  People with idiopathic PD (n=22) and age-matched and sex-matched comparisons (n=22) volunteered for the study.
  
  
  METHODS
  Not applicable, although a verbal-cognitive secondary task was used.
  
  
  METHODS
  The number of pegs placed in the Purdue Pegboard in 30 seconds, the number of correct verbal responses for the secondary task, scores on the Manual Ability Measure-16 test of hand function and, for the group with PD, ratings on the Unified Parkinson's Disease Rating Scale.
  
  
  RESULTS
  For the pegboard task, people with PD had reduced dexterity (t=-5.289; P<.001) compared with the unimpaired group. When the secondary task was added, both groups placed fewer pegs (F(1,42)=.652; P=.42). There were no differences between groups in scores for the subtraction task performed alone, but when this activity was carried out with the Purdue Pegboard Test, the number of correct responses declined only in the PD group (F(1,42)=4.90; P=.032).
  
  
  CONCLUSIONS
  Manual dexterity was compromised in this group of people with mild-moderate PD when compared with an unimpaired group. When the concurrent verbal-cognitive task was added, dual-task interference occurred in both groups but to a greater extent in people with PD.
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Physiotherapy, University of Melbourne, Melbourne, Australia. eproud@pgrad.unimelb.edu.au <eproud@pgrad.unimelb.edu.au>
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Proud
authors.forename: Meg E
authors.initials: ME
authors.lastname: Morris
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004185:Disability Evaluation; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D010300:Parkinson Disease / Q000503:physiopathology*; D013647:Task Performance and Analysis