title: Gait initiation in community-dwelling adults with Parkinson disease: comparison with older and younger adults without the disease.
abstract: OBJECTIVE
  Initiation of gait requires transitions from relatively stationary positions to stability with movement and from double- to single-limb stances. These are deliberately destabilizing activities that may be difficult for people with early Parkinson disease (PD), even when they have no problems with level walking. We studied differences in postural stability during gait initiation between participants with early and middle stages of PD (characterized by Hoehn and Yahr as stages 1-3) and 2 other groups of participants without PD--older and younger adults.
  
  
  METHODS
  The mean ages of the 3 groups of participants were as follows: subjects with PD, 69.3 years (SD=5.7, range=59-78); older subjects without PD, 69.0 years (SD=3.9, range=65-79); and younger subjects without PD, 27.5 (SD=3.9, range=22-35).
  
  
  METHODS
  A 3-dimensional motion analysis system was used with 2 force platforms to obtain data for center of mass (COM) and center of pressure (COP). The distance between the vertical projections of the COM and the COP (COM-COP distance) was used to reflect postural control during 5 events in gait initiation.
  
  
  RESULTS
  By use of multivariate analysis of variance, differences in COM-COP distance were found among the 3 groups. An analysis of variance indicated differences for 4 of the 5 events in gait initiation. A Scheffe post hoc analysis demonstrated differences in gait initiation between the subjects with PD and both groups of subjects without PD (2 events) and between the subjects with PD and the younger subjects without PD (2 events).
  
  
  CONCLUSIONS
  The COM-COP distance relationship was used to measure postural control during the transition from quiet standing to steady-state gait. Differences between groups indicated that individuals with impaired postural control allow less COM-COP distance than do individuals with no known neurologic problems. The method used could prove useful in the development and assessment of interventions to improve ambulation safety and enhance the independence of people with impaired postural control.
authors.affiliation: 64th Combat Support Hospital, US Army, Wurzburg, Germany.
authors.forename: Matthew
authors.initials: M
authors.lastname: Martin
authors.forename: Mindi
authors.initials: M
authors.lastname: Shinberg
authors.forename: Maggie
authors.initials: M
authors.lastname: Kuchibhatla
authors.forename: Laurie
authors.initials: L
authors.lastname: Ray
authors.forename: James J
authors.initials: JJ
authors.lastname: Carollo
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Schenkman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005684:Gait / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology* / Q000534:rehabilitation; D011187:Posture / Q000502:physiology*; D012016:Reference Values