title: Reliability and validity of a wireless accelerometer for the assessment of postural sway.
abstract: Clinicians are in need of valid and objective measures of postural sway. Accelerometers have been shown to be suitable alternatives to expensive and stationary force plates. We evaluated the test-retest reliability and balance task discrimination capability of a new wireless triaxial accelerometer (YEI 3-Space Sensor). Four testing conditions (eyes open or closed, while on a firm or compliant surface) were used to progressively challenge the static balance of 20 healthy male (n = 8) and female (n = 12) older adults (mean age 81 ± 4.3 y). Subjects completed 2 blocks of three 30-second trials per condition. The accelerometer was positioned on the lower back to acquire mediolateral (M-L) and anterior-posterior (A-P) accelerations. Intraclass correlation coefficients were all good to excellent, with values ranging from .736 to .972 for trial-to-trial and from .760 to .954 for block-to- block. A significant stepwise increase in center of mass acceleration root mean square values was found across the 4 balance conditions (F[1.49, 28.26] = 39.54, P < .001). The new accelerometer exhibited good to excellent trial-to-trial and block-to-block reliability and was sensitive to differences in visual and surface conditions and acceleration axes.
authors.affiliation: Health, Athletic Training, Recreation, and Kinesiology, Longwood University, Farmville, VA.
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Saunders
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Koutakis
authors.forename: Anne D
authors.initials: AD
authors.lastname: Kloos
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Kegelmeyer
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Dicke
authors.forename: Steven T
authors.initials: ST
authors.lastname: Devor
mesh_terms: D061725:Accelerometry / Q000295:instrumentation*; D056044:Actigraphy / Q000295:instrumentation*; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009068:Movement / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059015:Wireless Technology / Q000295:instrumentation*