title: Mechanical energy and power flow of the upper extremity in manual wheelchair propulsion.
abstract: OBJECTIVE
  To investigate the characteristics of mechanical energy and power flow of the upper limb during wheelchair propulsion.
  
  
  METHODS
  Mechanical energy and power flow of segments were calculated.
  
  
  BACKGROUND
  Very few studies have taken into account the mechanical energy and power flow of the musculoskeletal system during wheelchair propulsion. Mechanical energy and power flow have proven to be useful tools for investigating locomotion disorders during human gait.
  
  
  METHODS
  Twelve healthy male adults (mean age, 23.5 years) were recruited for this study. Three-dimensional kinematic and kinetic data of the upper extremity were collected during wheelchair propulsion using a Hi-Res Expert Vision system and an instrumented wheel, respectively.
  
  
  RESULTS
  During the initiation of the propulsion phase, joint power is generated in the upper arm or is transferred from the trunk downward to the forearm and hand to propel the wheel forward. During terminal propulsion, joint power is transferred upward to the trunk from the forearm and upper arm. The rate of change of mechanical energy and power flow for the forearm and hand have similar patterns, but the upper arm values differ.
  
  
  CONCLUSIONS
  Joint power plays an important role in energy transfer as well as the energy generated and absorbed by muscles spanning the joints during wheelchair propulsion.
  
  
  CONCLUSIONS
  Energy and power flow information during wheelchair propulsion allows us to gain a better understanding of the coordination of the movement by the musculoskeletal system.
authors.affiliation: Institute of Biomedical Engineering, National Cheng Kung University, 701, Tainan, Taiwan.
authors.forename: Lan-Yuen
authors.initials: LY
authors.lastname: Guo
authors.forename: Fong-Chin
authors.initials: FC
authors.lastname: Su
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Wu
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004734:Energy Metabolism / Q000502:physiology*; D004735:Energy Transfer / Q000502:physiology*; D005542:Forearm / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D019415:Torque; D034941:Upper Extremity / Q000502:physiology*; D014910:Wheelchairs