title: Seat cushion optimization: a comparison of interface pressure and tissue stiffness characteristics for spinal cord injured and elderly patients.
abstract: OBJECTIVE
  A method for designing tissue deformation minimizing seat surfaces was evaluated. Pressure and stiffness criteria were used to optimize surface shape. The method's efficacy for patients with spinal cord injuries (SCI) and a comparison of cushion performance and interface characteristics with a group of 30 elderly patients are presented.
  
  
  METHODS
  Repeated measures, prospective study.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  SCI (n=12), elderly (age 65 + years) [n=30].
  
  
  METHODS
  One flat and two custom foam seat cushions.
  
  
  METHODS
  Interface pressure measured using a pressure sensing pad; tissue stiffness and pressure recorded on a rigid programmable seat surface.
  
  
  RESULTS
  Pressure distributions on contoured cushions for the SCI group contained lower values than distributions on flat cushions. A comparison of the pressure data between the elderly and SCI showed that significant differences exist between interface characteristics. The SCI group had higher peak interface pressures for all cushions tested. Tissue stiffness measurements were similar for each group.
  
  
  CONCLUSIONS
  Results showed improved effectiveness of custom contoured foam seat cushions versus flat foam cushions. The results suggest that pressure distributions for SCI are more sensitive to support cushion characteristics than for the elderly. Further research is needed to determine the extent of the difference between the populations represented by these groups.
authors.affiliation: Department of Rehabilitation Science and Technology, School of Health and Rehabilitation Sciences, University of Pittsburgh, PA, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Brienza
authors.forename: P E
authors.initials: PE
authors.lastname: Karg
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D004867:Equipment Design; D006804:Ergonomics; D005260:Female; D006801:Humans; D007374:Interior Design and Furnishings; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D055585:Physical Phenomena; D010825:Physics; D003668:Pressure Ulcer / Q000517:prevention & control; D013119:Spinal Cord Injuries / Q000534:rehabilitation*