title: Clinical Markers of the Intensity of Balance Challenge: Observational Study of Older Adult Responses to Balance Tasks.
abstract: BACKGROUND
  Effective balance rehabilitation is critically important to the aging population. Optimal exercise prescription for balance rehabilitation has not been described, as there is no measure of balance exercise intensity. To rate the intensity of balance exercise, an item set is required.
  
  
  OBJECTIVE
  The aim of this study was to explore verbal and nonverbal markers that differentiated tasks of high, medium, and low balance intensity to inform the development of an instrument to measure the intensity of balance challenge.
  
  
  METHODS
  This was an observational study utilizing an interpretive description approach.
  
  
  METHODS
  Twenty older adults were observed performing 3 balance tasks that challenged balance at low to high intensity. Verbal and nonverbal responses were recorded. After each task, participants were asked to describe the test experience. Data were analyzed to identify potential markers of balance challenge intensity.
  
  
  RESULTS
  Markers of the intensity of balance challenge were grouped by time periods defined as pretask, in-task, and posttask. A key pretask finding was an increased delay to task commencement with increased task difficulty. Commencement delay was accompanied by talk in 19 of 21 instances. Physical markers of the intensity of balance challenge were grouped into 3 categories-bracing, postural reactions, and sway-and were increasingly observed as intensity of balance challenge increased. Participants described tasks as pushing them toward the limits of their balancing capacity as the intensity of balance challenge increased.
  
  
  CONCLUSIONS
  Verbal and nonverbal markers of the intensity of balance challenge in older adults performing balance tasks that differentiated high-intensity tasks from medium- to low-intensity tasks were identified. The pretask phase of balance exercise performance is an important diagnostic space, rich in verbal and nonverbal markers.
authors.affiliation: M.K. Farlie, BPhysio, PGradCertPhysio, GradCertHealthProfEd, Allied Health Research Unit, Monash Health, Kingston Centre, Warrigal Road, Cheltenham, Victoria 3192, Australia, and Faculty of Medicine Nursing and Health Sciences, Monash University, Melbourne, Australia. melanie.farlie@monashhealth.org.
authors.forename: Melanie K
authors.initials: MK
authors.lastname: Farlie
authors.affiliation: E. Molloy, PhD, BPhysio(Hons), Faculty of Medicine Nursing and Health Sciences, Monash University.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Molloy
authors.affiliation: J.L. Keating, PhD, BAppSc(Physiotherapy), PGradDipManipTher, Faculty of Medicine Nursing and Health Sciences, Monash University.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Keating
authors.affiliation: T.P. Haines, PhD, BPhysio(Hons), GradCertHealth Economics, Faculty of Medicine Nursing and Health Sciences, Monash University, and Allied Health Research Unit, Monash Health.
authors.forename: Terry P
authors.initials: TP
authors.lastname: Haines
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009633:Nonverbal Communication; D004856:Postural Balance / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012307:Risk Factors; D013647:Task Performance and Analysis; D014705:Verbal Behavior