Validity and reliability of the Swaymeter device for measuring postural sway

Daina L Sturnieks, Ria Arnold, Stephen R Lord, Daina L Sturnieks, Ria Arnold, Stephen R Lord

Abstract

Background: This study aimed to examine: 1) Swaymeter concurrent validity in discriminating between young and older adult populations; 2) Swaymeter convergent validity against a forceplate system; and 3) the immediate test-retest repeatability of postural sway measures obtained from the Swaymeter.

Methods: Twenty-nine older adults aged 71 to 83 years and 11 young adults aged 22 to 47 years had postural sway measured simultaneously with the Swaymeter and a forceplate for three repeat 30 second trials, under four conditions (floor eyes open, floor eyes closed, foam eyes open, foam eyes closed).

Results: Age-related differences in sway parameters across the four conditions were evident using the Swaymeter. Moderate-to-good correlations were found between Swaymeter and forceplate sway measures across conditions (r = 0.560-0.865). Good agreement between the Swaymeter and forceplate were found for anteroposterior and mediolateral sway displacement measures (average offset = 6 mm). Sway path length measures were longer for the forceplate compared to the Swaymeter (average offset = 376 mm), but these data showed good agreement following log-transformation. The Swaymeter was reliable across trials, with intraclass correlation coefficients ranging from 0.654 to 0.944.

Conclusions: The Swaymeter is a reliable tool for assessing postural sway and discriminates between performance of young and older people across multiple sensory conditions.

Figures

Figure 1
Figure 1
Pictorial representation of the assessment of postural sway using the Swaymeter and forceplate systems.
Figure 2
Figure 2
Bland-Altman plots of: a) AP displacement (mm); b) ML displacement (mm); c) sway path length (mm); and d) log sway path length, for Swaymeter versus forceplate (COP) comparisons during the foam eyes open condition. The dashed grey lines represent the limits of agreement (95%CI) from the mean difference, represented by the solid grey line.

References

    1. Baloh RW, Fife TD, Zwerling L, Socotch T, Jacobson K, Bell T, Beykirch K. Comparison of static and dynamic posturography in young and older normal people. J Am Geriatr Soc. 1994;42(4):405–12.
    1. Hellbrandt FA, Braun GL. The influence of sex and age on the postural sway of man. Am J Phys Anthropol. 1939;24(3):347–360. doi: 10.1002/ajpa.1330240318.
    1. Piirtola M, Era P. Force platform measurements as predictors of falls among older people - a review. Gerontology. 2006;52(1):1–16. doi: 10.1159/000089820.
    1. Lord SR, Castell S. Physical activity program for older persons: effect on balance, strength, neuromuscular control, and reaction time. Arch Phys Med Rehabil. 1994;75(6):648–52. doi: 10.1016/0003-9993(94)90187-2.
    1. Maki BE, Holliday PJ, Topper AK. A prospective study of postural balance and risk of falling in an ambulatory and independent elderly population. Journal of Gerontology. 1994;49(2):M72–84.
    1. Brooke-Wavell K, Prelevic GM, Bakridan C, Ginsburg J. Effects of physical activity and menopausal hormone replacement therapy on postural stability in postmenopausal women--a cross-sectional study. Maturitas. 2001;37(3):167–72. doi: 10.1016/S0378-5122(00)00182-1.
    1. Chang AT, Seale H, Walsh J, Brauer SG. Static balance is affected following an exercise task in chronic obstructive pulmonary disease. J Cardiopulm Rehabil Prev. 2008;28(2):142–5.
    1. Hinman RS, Bennell KL, Metcalf BR, Crossley KM. Balance impairments in individuals with symptomatic knee osteoarthritis: a comparison with matched controls using clinical tests. Rheumatology (Oxford) 2002;41(12):1388–94. doi: 10.1093/rheumatology/41.12.1388.
    1. Lord SR, McLean D, Stathers G. Physiological factors associated with injurious falls in older people living in the community. Gerontology. 1992;38(6):338–46. doi: 10.1159/000213351.
    1. Lord SR, Sambrook PN, Gilbert C, Kelly PJ, Nguyen T, Webster IW, Eisman JA. Postural stability, falls and fractures in the elderly: results from the Dubbo Osteoporosis Epidemiology Study. Medical Journal of Australia. 1994;160(11):684–5. 688-91.
    1. Lord SR, Clark RD. Simple physiological and clinical tests for the accurate prediction of falling in older people. Gerontology. 1996;42(4):199–203. doi: 10.1159/000213793.
    1. Lord SR, Ward JA, Williams P, Anstey KJ. Physiological factors associated with falls in older community-dwelling women. J Am Geriatr Soc. 1994;42(10):1110–7.
    1. Folstein MF, Folstein SE, McHugh PR. "Mini-Mental state": a practical method for grading the cognitive status of patients for the clinician. J Psychiatr Res. 1975;12:189–98. doi: 10.1016/0022-3956(75)90026-6.
    1. Lord SR, Clark RD, Webster IW. Postural stability and associated physiological factors in a population of aged persons. J Gerontol. 1991;46(3):M69–76.
    1. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986;1(8476):307–10.
    1. Lord SR, Menz HB, Tiedemann A. A physiological profile approach to falls risk assessment and prevention. Phys Ther. 2003;83(3):237–52.
    1. Winter DA, Patla AE, Prince F, Ishac M, Gielo-Perczak K. Stiffness control of balance in quiet standing. J Neurophysiol. 1998;80(3):1211–21.
    1. Lin D, Seol H, Nussbaum MA, Madigan ML. Reliability of COP-based postural sway measures and age-related differences. Gait Posture. 2008;28(2):337–42. doi: 10.1016/j.gaitpost.2008.01.005.
    1. Lafond D, Corriveau H, Hebert R, Prince F. Intrasession reliability of center of pressure measures of postural steadiness in healthy elderly people. Arch Phys Med Rehabil. 2004;85(6):896–901. doi: 10.1016/j.apmr.2003.08.089.
    1. Lord SR, Ward JA. Age-associated differences in sensori-motor function and balance in community dwelling women. Age Ageing. 1994;23(6):452–60. doi: 10.1093/ageing/23.6.452.
    1. Centre for Health Advancement and Centre for Epidemiology and Research. NSW Department of Health. Sydney; 2010. New South Wales Falls Prevention Baseline Survey: 2009 Report.
    1. Lord SR, Clark RD, Webster IW. Physiological factors associated with falls in an elderly population. Journal of the American Geriatrics Society. 1991;39(12):1194–200.

Source: PubMed

Sponsorit ja yhteistyökumppanit

Sairaudet

Huumeiden interventiot

3
Tilaa