title: Comparison of mirror, raw video, and real-time visual biofeedback for training toe-out gait in individuals with knee osteoarthritis.
abstract: OBJECTIVE
  To compare performance error and perceived difficulty during toe-out gait modification in people with knee osteoarthritis (OA) across 3 different types of visual feedback: mirror, raw video, and real-time biofeedback of toe-out angle.
  
  
  METHODS
  Repeated-measures, within-subject trial.
  
  
  METHODS
  University motion analysis laboratory.
  
  
  METHODS
  Individuals with knee OA (N=20; 11 women; mean age, 65.4±9.8y) participated in this study. Seven participants had mild knee OA, 9 had moderate knee OA, and 4 had severe knee OA.
  
  
  METHODS
  Participants were trained to walk on a treadmill while matching a target indicating a 10° increase in stance phase toe-out compared with toe-out angle measured during self-selected walking. The target was provided visually via the 3 types of feedback listed above and were presented in a random order.
  
  
  METHODS
  Kinematic data were collected and used to calculate the difference between the target angle and the actual performed angle for each condition (toe-out performance error). Difficulty was assessed using a numerical rating scale (0-10) provided verbally by participants.
  
  
  RESULTS
  Toe-out performance error was significantly less when using the real-time biofeedback method than when using the other 2 methods (P=.025; mean difference vs mirror=2.05°; mean difference vs raw video=1.51°). Perceived difficulty was not statistically different between the groups (P=.51).
  
  
  CONCLUSIONS
  Although statistically significant, the 2° difference in toe-out gait performance error may not necessitate the large economic and personnel costs of real-time biofeedback as a means to modify movement in clinical or research settings.
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada. Electronic address: michael.hunt@ubc.ca.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Hunt
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Judit
authors.initials: J
authors.lastname: Takacs
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Katie
authors.initials: K
authors.lastname: Hart
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Erika
authors.initials: E
authors.lastname: Massong
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Keri
authors.initials: K
authors.lastname: Fuchko
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Biegler
mesh_terms: D000368:Aged; D001676:Biofeedback, Psychology / Q000379:methods*; D001696:Biomechanical Phenomena; D003626:Data Display; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000534:rehabilitation*; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*
keywords: Exercise movement techniques; Feedback; Gait; Knee osteoarthritis; Rehabilitation