title: A method for performance comparison of polycentric knees and its application to the design of a knee for developing countries.
abstract: BACKGROUND
  Polycentric knees for transfemoral prostheses have a variety of geometries, but a survey of literature shows that there are few ways of comparing their performance.
  
  
  OBJECTIVE
  Our objective was to present a method for performance comparison of polycentric knee geometries and design a new geometry.
  
  
  METHODS
  In this work, we define parameters to compare various commercially available prosthetic knees in terms of their stability, toe clearance, maximum flexion, and so on and optimize the parameters to obtain a new knee design.
  
  
  METHODS
  We use the defined parameters and optimization to design a new knee geometry that provides the greater stability and toe clearance necessary to navigate uneven terrain which is typically encountered in developing countries.
  
  
  RESULTS
  Several commercial knees were compared based on the defined parameters to determine their suitability for uneven terrain. A new knee was designed based on optimization of these parameters. Preliminary user testing indicates that the new knee is very stable and easy to use.
  
  
  CONCLUSIONS
  The methodology can be used for better knee selection and design of more customized knee geometries. Clinical relevance The method provides a tool to aid in the selection and design of polycentric knees for transfemoral prostheses.
authors.affiliation: Indian Institute of Technology Madras, Chennai, India.
authors.forename: T S
authors.initials: TS
authors.lastname: Anand
authors.affiliation: Indian Institute of Technology Madras, Chennai, India.
authors.forename: S
authors.initials: S
authors.lastname: Sujatha
mesh_terms: D003906:Developing Countries; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D007720:Knee Prosthesis; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology
keywords: Biomechanics; biomechanics of prosthetic/orthotic devices; developing countries; four-bar knee; polycentric knee; prosthetic design; prosthetics; prosthetics and orthotics in developing countries; toe clearance; uneven terrain