title: Safety and function of a prototype microprocessor-controlled knee prosthesis for low active transfemoral amputees switching from a mechanic knee prosthesis: a pilot study.
abstract: Aim of this pilot study was to assess safety and functioning of a microprocessor-controlled knee prosthesis (MPK) after a short familiarization time and no structured physical therapy.
  
  
  
  Five elderly, low-active transfemoral amputees who were fitted with a standard non-microprocessor controlled knee prosthesis (NMPK) performed a baseline measurement consisting of a 3 D gait analysis, functional tests and questionnaires. The first follow-up consisted of the same test procedure and was performed with the MPK after 4 to 6 weeks of familiarization. After being refitted to their standard NMPK again, the subjects undertook the second follow-up which consisted of solely questionnaires 4 weeks later.
  
  
  
  Questionnaires and functional tests showed an increase in the perception of safety. Moreover, gait analysis revealed more physiologic knee and hip extension/flexion patterns when using the MPK.
  
  
  
  Our results showed that although the Genium with Cenior-Leg ruleset-MPK (GCL-MPK) might help to improve several safety-related outcomes as well as gait biomechanics the functional potential of the GCL-MPK may have been limited without specific training and a sufficient acclimation period. Implications for Rehabilitation Elderly transfemoral amputees are often limited in their activity by safety issues as well as insufficient functioning regarding the non microprocessor-controlled knee prostheses (NMPK), thing that could be eliminated with the use of suitable microprocessor-controlled prostheses (MPK). The safety and functioning of a prototype MPK (GCL-MPK) specifically designed for the needs of older and low-active transfemoral amputees was assessed in this pilot study. The GCL-MPK showed indicators of increased safety and more natural walking patterns in older and low-active transfemoral amputees in comparison to the standard NMPK already after a short acclimatisation time and no structured physical therapy. Regarding functional performance it seems as if providing older and low-active transfemoral amputees with the GCL-MPK alone without prescribing structured prosthesis training might be insufficient to achieve improvements over the standard NMPKs.
authors.affiliation: a Department of Physical Medicine, Rehabilitation and Occupational Medicine , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Timothy
authors.initials: T
authors.lastname: Hasenoehrl
authors.affiliation: b Otto Bock Healthcare Department of Research/Biomechanics , Göttingen , Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmalz
authors.affiliation: c Department of Orthopaedic Surgery , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windhager
authors.affiliation: d Orthopaedic Rehabilitation Center Zicksee , St. Andrä am Zicksee , Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Domayer
authors.affiliation: a Department of Physical Medicine, Rehabilitation and Occupational Medicine , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Sara
authors.initials: S
authors.lastname: Dana
authors.affiliation: a Department of Physical Medicine, Rehabilitation and Occupational Medicine , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Ambrozy
authors.affiliation: a Department of Physical Medicine, Rehabilitation and Occupational Medicine , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Stefano
authors.initials: S
authors.lastname: Palma
authors.affiliation: a Department of Physical Medicine, Rehabilitation and Occupational Medicine , Medical University of Vienna, General Hospital of Vienna , Vienna , Austria.
authors.forename: Richard
authors.initials: R
authors.lastname: Crevenna
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D004185:Disability Evaluation; D005260:Female; D005269:Femur; D005684:Gait / Q000502:physiology; D006304:Health Status; D006801:Humans; D007398:Interpersonal Relations; D007720:Knee Prosthesis; D008297:Male; D008603:Mental Health; D008838:Microcomputers; D008875:Middle Aged; D026741:Physical Therapy Modalities; D010865:Pilot Projects; D011474:Prosthesis Design / Q000295:instrumentation*; D011788:Quality of Life
keywords: K2 ambulators; Microprocessor-controlled knee prosthesis; gait analysis; mechanic knee prosthesis; transfemoral amputees