title: Influence of hand-rim wheelchairs with rear suspension on seat forces and head acceleration during curb descent landings.
abstract: OBJECTIVE
  Shocks and vibrations experienced while using a hand-rim wheelchair can contribute to discomfort, fatigue and injury. The aim of this study was to compare the seat forces and head accelerations experienced by manual wheelchair users during independent curb descent landings in a standard and 3 suspension-type rigid-frame wheelchairs.
  
  
  METHODS
  
  
  
  METHODS
  repeated measures analysis of variance.
  
  
  METHODS
  Eight men with paraplegia due to spinal cord injury.
  
  
  METHODS
  Participants performed independently-controlled curb descent maneuvers with 4 wheelchairs. The seat force and head accelerations were compared across wheelchairs.
  
  
  RESULTS
  The suspension-type wheelchairs decreased the seat force and head accelerations by significantly (p < 0.05) extending the force rise time. Also, the seat force and head accelerations were inversely related to the seat force at initial contact. The monoshock-based suspension wheelchairs showed the least seat force and longest force rise time.
  
  
  CONCLUSIONS
  Suspension systems result in softer landings by attenuating the magnitude and time duration of the force and reducing head accelerations. Hand-rim wheelchair users can also soften landings by utilizing a "pull-up" strategy that reduces the force and head accelerations. Softer landings can contribute to improved ride quality.
authors.affiliation: Rehabilitation Engineering Program, Rancho Los Amigos National Rehabilitation Center, 7601 E. Imperial Highway, Building 500, Room 64, Downey, CA, USA. prequejo@larei.org
authors.forename: Philip S
authors.initials: PS
authors.lastname: Requejo
authors.forename: Somboon
authors.initials: S
authors.lastname: Maneekobkunwong
authors.forename: Jill
authors.initials: J
authors.lastname: McNitt-Gray
authors.forename: Rodney
authors.initials: R
authors.lastname: Adkins
authors.forename: Robert
authors.initials: R
authors.lastname: Waters
mesh_terms: D000054:Acceleration; D000328:Adult; D001696:Biomechanical Phenomena; D004867:Equipment Design; D006801:Humans; D008297:Male; D008328:Man-Machine Systems; D010264:Paraplegia / Q000503:physiopathology / Q000534:rehabilitation; D005082:Physical Exertion; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D013312:Stress, Physiological; D014732:Vibration / Q000009:adverse effects; D014910:Wheelchairs / Q000009:adverse effects