title: Kinetics of transfemoral amputees with osseointegrated fixation performing common activities of daily living.
abstract: BACKGROUND
  Direct anchorage of a lower-limb prosthesis to the bone through an implanted fixation (osseointegration) has been suggested as an excellent alternative for amputees experiencing complications from use of a conventional socket-type prosthesis. However, an attempt needs to be made to optimize the mechanical design of the fixation and refine the rehabilitation program. Understanding the load applied on the fixation is a crucial step towards this goal.
  
  
  METHODS
  The load applied on the osseointegrated fixation of nine transfemoral amputees was measured using a load transducer, when the amputees performed activities which included straight-line level walking, ascending and descending stairs and a ramp as well as walking around a circle. Force and moment patterns along each gait cycle, magnitudes and time of occurrence of the local extrema of the load, as well as impulses were analysed.
  
  
  RESULTS
  Managing a ramp and stairs, and walking around a circle did not produce a significant increase (P>0.05) in load compared to straight-line level walking. The patterns of the moment about the medio-lateral axis were different among the six activities which may reflect the different strategies used in controlling the prosthetic knee joint.
  
  
  CONCLUSIONS
  This study increases the understanding of biomechanics of bone-anchored osseointegrated prostheses. The loading data provided will be useful in designing the osseointegrated fixation to increase the fatigue life and to refine the rehabilitation protocol.
authors.affiliation: School of Engineering Systems, Queensland University of Technology, Brisbane, Australia. wc.lee@qut.edu.au <wc.lee@qut.edu.au>
authors.forename: Winson C C
authors.initials: WC
authors.lastname: Lee
authors.forename: Laurent A
authors.initials: LA
authors.lastname: Frossard
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hagberg
authors.forename: Eva
authors.initials: E
authors.lastname: Haggstrom
authors.forename: Rickard
authors.initials: R
authors.lastname: Brånemark
authors.forename: John H
authors.initials: JH
authors.lastname: Evans
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Pearcy
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D012399:Rotation; D014159:Transducers