title: Comparison of muscle and skin perfusion over the ischial tuberosities in response to wheelchair tilt-in-space and recline angles in people with spinal cord injury.
abstract: OBJECTIVE
  To compare the efficacy of wheelchair tilt-in-space and recline on enhancing muscle and skin perfusion over the ischial tuberosities in people with spinal cord injury (SCI).
  
  
  METHODS
  Repeated-measures and before-after trial design.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Power wheelchair users with SCI (N=20).
  
  
  METHODS
  Six combinations of wheelchair tilt-in-space and recline angles were presented to participants in a random order. The testing protocol consisted of a baseline 5 minutes sitting with no tilt/recline and 5 minutes positioned in a tilted and reclined position at each of 6 conditions, including: (1) 15° tilt-in-space and 100° recline, (2) 25° tilt-in-space and 100° recline, (3) 35° tilt-in-space and 100° recline, (4) 15° tilt-in-space and 120° recline, (5) 25° tilt-in-space and 120° recline, and (6) 35° tilt-in-space and 120° recline.
  
  
  METHODS
  Muscle and skin perfusion were assessed by near-infrared spectroscopy and laser Doppler flowmetry, respectively.
  
  
  RESULTS
  Muscle perfusion was significantly increased at 25° and 35° tilt-in-space when combined with 120° recline, and skin perfusion was significantly increased at 3 tilt-in-space angles (15°, 25°, 35°) when combined with 120° recline and at 35° tilt-in-space when combined with 100° recline (P<.05). Even in the positions of increased muscle perfusion and skin perfusion (25° and 35° of tilt-in-space combined with 120° of recline), the amount of muscle perfusion change was significantly lower than the amount of skin perfusion change (P<.05).
  
  
  CONCLUSIONS
  Our results indicate that a larger angle of tilt-in-space and recline is needed to improve muscle perfusion compared with skin perfusion. A position of 25° tilt-in-space combined with 120° recline is effective in enhancing muscle and skin perfusion of weight-bearing soft tissues at the ischial tuberosities.
authors.affiliation: Rehabilitation Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL. Electronic address: yjan@illinois.edu.
authors.forename: Yih-Kuen
authors.initials: YK
authors.lastname: Jan
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Crane
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Liao
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Woods
authors.forename: William J
authors.initials: WJ
authors.lastname: Ennis
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D006801:Humans; D007512:Ischium; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000098:blood supply*; D056888:Patient Positioning / Q000379:methods*; D003668:Pressure Ulcer / Q000517:prevention & control; D012867:Skin / Q000098:blood supply*; D013055:Spectrophotometry, Infrared; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D016474:Weight-Bearing; D014910:Wheelchairs
keywords: DTI; LDF; Laser-Doppler flowmetry; NIRS; NPUAP; National Pressure Ulcer Advisory Panel; Rehabilitation; SCI; Spectroscopy, near-infrared; Sto(2); Wheelchairs; deep tissue injury; laser Doppler flowmetry; near-infrared spectroscopy; saturation of tissue oxygen; spinal cord injury