title: A perturbation-based balance training program for older adults: study protocol for a randomised controlled trial.
abstract: BACKGROUND
  Previous research investigating exercise as a means of falls prevention in older adults has shown mixed results. Lack of specificity of the intervention may be an important factor contributing to negative results. Change-in-support (CIS) balance reactions, which involve very rapid stepping or grasping movements of the limbs, play a critical role in preventing falls; hence, a training program that improves ability to execute effective CIS reactions could potentially have a profound effect in reducing risk of falling. This paper describes: 1) the development of a perturbation-based balance training program that targets specific previously-reported age-related impairments in CIS reactions, and 2) a study protocol to evaluate the efficacy of this new training program.
  
  
  METHODS
  The training program involves use of unpredictable, multi-directional moving-platform perturbations to evoke stepping and grasping reactions. Perturbation magnitude is gradually increased over the course of the 6-week program, and concurrent cognitive and movement tasks are included during later sessions. The program was developed in accordance with well-established principles of motor learning, such as individualisation, specificity, overload, adaptation-progression and variability. Specific goals are to reduce the frequency of multiple-step responses, reduce the frequency of collisions between the stepping foot and stance leg, and increase the speed of grasping reactions. A randomised control trial will be performed to evaluate the efficacy of the training program. A total of 30 community-dwelling older adults (age 64-80) with a recent history of instability or falling will be assigned to either the perturbation-based training or a control group (flexibility/relaxation training), using a stratified randomisation that controls for gender, age and baseline stepping/grasping performance. CIS reactions will be tested immediately before and after the six weeks of training, using platform perturbations as well as a distinctly different method of perturbation (waist pulls) in order to evaluate the generalisability of the training effects.
  
  
  CONCLUSIONS
  This study will determine whether perturbation-based balance training can help to reverse specific age-related impairments in balance-recovery reactions. These results will help to guide the development of more effective falls prevention programs, which may ultimately lead to reduced health-care costs and enhanced mobility, independence and quality of life.
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada. avril.mansfield@utoronto.ca
authors.forename: Avril
authors.initials: A
authors.lastname: Mansfield
authors.forename: Amy L
authors.initials: AL
authors.lastname: Peters
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Liu
authors.forename: Brian E
authors.initials: BE
authors.lastname: Maki
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011379:Prognosis; D012016:Reference Values; D012307:Risk Factors; D012737:Sex Factors; D016037:Single-Blind Method; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology