title: Lower-leg inertial properties in transtibial amputees and control subjects and their influence on the swing phase during gait.
abstract: OBJECTIVE
  To identify the factors that constitute optimal inertial properties for a lower-limb prosthesis.
  
  
  METHODS
  Experimental, controlled; simulation using a subject-specific double-pendulum model based on individual kinematic data and leg inertial properties. Simulation outcomes were compared with gait analysis data.
  
  
  METHODS
  A gait laboratory.
  
  
  METHODS
  Ten transtibial amputees and 10 matched healthy controls.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Inertial properties of the lower leg; kinematics and kinetics of the swing phase; and kinematics of double-pendulum model simulations.
  
  
  RESULTS
  In all amputees, inertial properties were reduced. No between-group differences existed in kinematics; hip and knee joint torques and powers were reduced in the amputees. Deviations between the double-pendulum model and experimental data were larger in the amputees than in the control subjects.
  
  
  CONCLUSIONS
  Although current lightweight prostheses have less optimal pendular behavior, their light weight requires smaller joint torques to influence the pendular trajectory. Therefore, optimal inertial properties, in terms of swing phase kinematics and kinetics, will be a compromise between pendular properties and efficient control.
authors.affiliation: Institute of Rehabilitation Medicine, Erasmus University Rotterdam, Rotterdam, The Netherlands. rselles@northwestern.edu
authors.forename: Ruud W
authors.initials: RW
authors.lastname: Selles
authors.forename: Sabine
authors.initials: S
authors.lastname: Korteland
authors.forename: A J
authors.initials: AJ
authors.lastname: Van Soest
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Bussmann
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Stam
mesh_terms: D000328:Adult; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D007866:Leg / Q000502:physiology; D008297:Male; D019415:Torque; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology