title: Periodically relieving ischial sitting load to decrease the risk of pressure ulcers.
abstract: OBJECTIVE
  To investigate the relieving effect on interface pressure of an alternate sitting protocol involving a sitting posture that reduces ischial support.
  
  
  METHODS
  Repeated measures in 2 protocols on 3 groups of subjects.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Twenty able-bodied persons, 20 persons with paraplegia, and 20 persons with tetraplegia.
  
  
  METHODS
  Two 1-hour protocols were used: alternate and normal plus pushup. In the alternate protocol, sitting posture was alternated every 10 minutes between normal (sitting upright with ischial support) and with partially removed ischial support (WO-BPS) postures; in the normal plus pushup protocol, sitting was in normal posture with pushups (lifting the subject off the seat) performed every 20 minutes.
  
  
  METHODS
  Interface pressure on seat and backrest.
  
  
  RESULTS
  In WO-BPS posture, the concentrated interface pressure observed around the ischia in normal posture was significantly repositioned to the thighs. By cyclically repositioning the interface pressure, the alternate protocol was superior to the normal plus pushup protocol in terms of a significantly lower average interface pressure over the buttocks.
  
  
  CONCLUSIONS
  A sitting protocol periodically reducing the ischial support helps lower the sitting load on the buttocks, especially the area close to ischial tuberosities.
authors.affiliation: Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL 60611, USA. m-makhsous2@northwestern.edu
authors.forename: Mohsen
authors.initials: M
authors.lastname: Makhsous
authors.forename: Diane M
authors.initials: DM
authors.lastname: Rowles
authors.forename: William Z
authors.initials: WZ
authors.lastname: Rymer
authors.forename: James
authors.initials: J
authors.lastname: Bankard
authors.forename: Ellis K
authors.initials: EK
authors.lastname: Nam
authors.forename: David
authors.initials: D
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Lin
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007512:Ischium / Q000502:physiology*; D008297:Male; D010264:Paraplegia / Q000503:physiopathology; D011187:Posture / Q000502:physiology*; D011312:Pressure; D003668:Pressure Ulcer / Q000503:physiopathology / Q000517:prevention & control*; D011782:Quadriplegia / Q000503:physiopathology; D016474:Weight-Bearing / Q000502:physiology*; D014910:Wheelchairs