title: Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee.
abstract: OBJECTIVE
  To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies.
  
  
  METHODS
  A-B-A-B reversal design.
  
  
  METHODS
  Home, community, and laboratory environments.
  
  
  METHODS
  Twenty-one unilateral, transfemoral amputees.
  
  
  METHODS
  Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg).
  
  
  METHODS
  Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation.
  
  
  RESULTS
  Stair descent score, hill descent time, and hill sound-side step length showed significant (P<.01) improvement with the C-Leg. Users reported a significant (P<.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly (P<.001) greater than the mechanical control prosthesis.
  
  
  CONCLUSIONS
  The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.
authors.affiliation: Prosthetics Research Study, Seattle, WA 98104, USA. brian.hafner@prs-research.org
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Hafner
authors.forename: Laura L
authors.initials: LL
authors.lastname: Willingham
authors.forename: Noelle C
authors.initials: NC
authors.lastname: Buell
authors.forename: Katheryn J
authors.initials: KJ
authors.lastname: Allyn
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Smith
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D017060:Patient Satisfaction; D011474:Prosthesis Design; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology*