title: The influence of a powered knee-ankle-foot orthosis on walking in poliomyelitis subjects: A pilot study.
abstract: BACKGROUND
  Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait.
  
  
  OBJECTIVE
  The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation.
  
  
  METHODS
  Quasi-experimental design.
  
  
  METHODS
  Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system.
  
  
  RESULTS
  Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis.
  
  
  CONCLUSIONS
  The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis.
  
  
  CONCLUSIONS
  This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities.
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Arazpour
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Moradi
authors.affiliation: Loghman Hakim hospital, Shahid Beheshti University of Medical Sciences, Department of Neurosurgery, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samadian
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran Ma.bahramizadeh@uswr.ac.ir.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Bahramizadeh
authors.affiliation: The University of Sheffield, Sheffield, UK.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Joghtaei
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran.
authors.forename: Monireh
authors.initials: M
authors.lastname: Ahmadi Bani
authors.affiliation: IHSCR, Faculty of Health & Social Care, University of Salford, Manchester, Salford, UK.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Hutchins
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Mardani
mesh_terms: D000842:Ankle; D015331:Cohort Studies; D004867:Equipment Design; D005528:Foot; D005684:Gait / Q000502:physiology*; D006801:Humans; D007717:Knee; D008297:Male; D008875:Middle Aged; D009989:Orthotic Devices / Q000145:classification*; D010865:Pilot Projects; D011051:Poliomyelitis / Q000175:diagnosis / Q000534:rehabilitation*; D011209:Power, Psychological; D016138:Walking / Q000502:physiology*
keywords: Powered knee–ankle–foot orthosis; kinematics; poliomyelitis; temporospatial; walking