title: The effects of body mass index on peak seat-interface pressure of institutionalized elderly.
abstract: OBJECTIVE
  To determine if body mass index (BMI) influenced seat-interface pressure in a population of institutionalized elderly.
  
  
  METHODS
  A cross-sectional comparison of peak seat-interface pressure in 4 groups of institutionalized elderly was compared with BMI scores defined as either thin (<20 kg/m(2)), desirable range (20-24.9 kg/m(2)), grade I obesity (25-29.9 kg/m(2)), or grade II obesity (30-40 kg/m(2)).
  
  
  METHODS
  Several small nursing homes and a university in a small urban community.
  
  
  METHODS
  A convenience sample of 75 individuals (age range, 65-95 y) living in 1 of 3 skilled nursing facilities.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The Novel Pliance seat pressure-mapping system was used to collect seat-interface pressure data. Each participant was asked to sit in the wheelchair for up to 10 minutes while the seat-interface pressures were recorded. Body weight and height of each participant were obtained from the medical chart; these characteristics were then used to calculate a BMI for each participant.
  
  
  RESULTS
  A 1-way analysis of variance on the peak seat-interface pressures revealed significant differences between the 4 groups (P<.05). Post hoc comparisons showed differences in peak seat-interface pressure between the thin and desirable range groups (P<.05), the thin and grade I obesity group (P<.05), and the thin and grade II obesity groups (P<.05). Differences in peak seat-interface pressure decreased as BMI increased.
  
  
  CONCLUSIONS
  The results are consistent with the results of a previous study of individuals with spinal cord injuries. In the current study, peak seat-interface pressure was highest in the thin elderly group, which had the lowest BMI levels of any of the 4 groups. Differences in the peak seat-interface pressures were less as BMI increased.
authors.affiliation: Physical Therapy Department, University of Wisconsin-La Crosse, Health Science Center, La Crosse, WI 54601, USA. kernozek.thom@uwlax.edu
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kernozek
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Wilder
authors.forename: Alissa
authors.initials: A
authors.lastname: Amundson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hummer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015992:Body Mass Index; D002081:Buttocks / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D006707:Homes for the Aged; D006801:Humans; D008297:Male; D009735:Nursing Homes; D009765:Obesity / Q000503:physiopathology; D011312:Pressure; D003668:Pressure Ulcer / Q000517:prevention & control*; D014910:Wheelchairs