title: Impact of sitting time on seat-interface pressure and on pressure mapping with multiple sclerosis patients.
abstract: OBJECTIVE
  To examine changes in seat-interface pressure with multiple sclerosis (MS) patients.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Multiple Sclerosis Society's Resource Centre and community.
  
  
  METHODS
  Convenience sample of 15 MS wheelchair users and 12 MS non-wheelchair users.
  
  
  METHODS
  Interface pressure was measured for 8 minutes using the Force Sensing Array pressure mapping system.
  
  
  METHODS
  Number of activated sensors, standard deviation, average and maximum pressures.
  
  
  RESULTS
  With the wheelchair users, significant decreases were found in the standard deviation and average and maximum pressures during 0 to 2 minutes of sitting ( P <.01). Average pressure was the only parameter to show a significant decrease in the non-wheelchair users ( P <.01) during 0 to 2 minutes. Significant increases were found in all output parameters during 2 to 4 minutes with both groups ( P <.05). Non-wheelchair users showed no significant changes in the output parameters after 4 minutes, but wheelchair users showed significant continued increases in the output parameters from 4 to 8 minutes ( P <.05).
  
  
  CONCLUSIONS
  Because no significant changes in interface pressure occurred after 4 minutes of sitting with the non-wheelchair users, 4 minutes may be a reasonable sitting time before interface pressure is recorded with this group. Significant changes in interface pressure continued up to 8 minutes with the wheelchair users, therefore 8 minutes or beyond may be a reasonable sitting time before recording with this group.
authors.affiliation: Health and Rehabilitation Sciences Research Institute, University of Ulster at Jordanstown, Shore Road, Newtownabbey, County Antrim, Northern Ireland BT37 0QB.
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Crawford
authors.forename: May D
authors.initials: MD
authors.lastname: Stinson
authors.forename: Deirdre M
authors.initials: DM
authors.lastname: Walsh
authors.forename: Alison P
authors.initials: AP
authors.lastname: Porter-Armstrong
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008328:Man-Machine Systems; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D010865:Pilot Projects; D011187:Posture / Q000502:physiology*; D011312:Pressure; D003668:Pressure Ulcer / Q000503:physiopathology; D013997:Time Factors; D014910:Wheelchairs