title: Load redistribution in variable position wheelchairs in people with spinal cord injury.
abstract: OBJECTIVE
  Tilt and recline variable position seating systems are most commonly used for pressure relief to decrease potential for skin breakdown. This study provides quantitative information on the magnitudes of loading on the seat and back during phases of tilt, recline, and standing. The objective of this study was to show that the amount of force reduction at the seat would differ across these 3 methods within their respective clinical ranges.
  
  
  METHODS
  Six able-bodied (AB) subjects (2 men, 4 women) with a median age of 25 years, and 10 subjects (8 men, 2 women) with spinal cord injury (SCI) with a median age of 35.5 years.
  
  
  METHODS
  Subjects sat on a power wheelchair with Tekscan pressure mats placed underneath a foam backrest and cushion. Data were collected at 5 positions for each method. Order of position and method tested were randomized. Linear regressions were used to calculate the relationships of normalized seat and backrest forces to seat and backrest angles for each chair configuration.
  
  
  RESULTS
  Normalized seat loads had strong linear relationships with the angles of change in tilt, recline, and standing for both groups. Maximum decreases in seat load occurred at full standing and full recline in the SCI subjects and in full standing in the AB subjects. Loads linearly increased on the back during tilt and recline and linearly decreased during standing for both groups.
  
  
  CONCLUSIONS
  Standing and recline offered similar seat load reductions at their respective terminal positions. Standing also reduced loading on the backrest. Recognizing that each method had clinical benefits and drawbacks, the results of this study indicate that tilt, recline, and standing systems should be considered as a means of weight shifting for wheelchair users.
authors.affiliation: Center for Assistive Technology and Environmental Access, Georgia Institute of Technology, Atlanta, Georgia, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sprigle
authors.forename: Christine
authors.initials: C
authors.lastname: Maurer
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Soneblum
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Sorenblum
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008328:Man-Machine Systems; D009068:Movement / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology* / Q000534:rehabilitation; D014910:Wheelchairs; D055815:Young Adult
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