title: The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion.
abstract: BACKGROUND
  The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns.
  
  
  METHODS
  Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s.
  
  
  RESULTS
  The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects.
  
  
  CONCLUSIONS
  The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration.
authors.affiliation: Department of Biomedical Engineering, National Cheng Kung University, 1 University Road, Tainan City 701, Taiwan.
authors.forename: Chung-Ying
authors.initials: CY
authors.lastname: Tsai
authors.forename: Chien-Ju
authors.initials: CJ
authors.lastname: Lin
authors.forename: Yueh-Chu
authors.initials: YC
authors.lastname: Huang
authors.forename: Po-Chou
authors.initials: PC
authors.lastname: Lin
authors.forename: Fong-Chin
authors.initials: FC
authors.lastname: Su
mesh_terms: D001696:Biomechanical Phenomena; D004867:Equipment Design; D006801:Humans; D055595:Mechanical Phenomena; D009068:Movement; D016059:Range of Motion, Articular; D012785:Shoulder Joint / Q000502:physiology; D062211:Spatio-Temporal Analysis; D034941:Upper Extremity / Q000502:physiology*; D014910:Wheelchairs; D014955:Wrist Joint / Q000502:physiology; D055815:Young Adult