RESEARCH REPORT POSTER DISPLAY

ASSESSMENT OF PHYSICAL ACTIVITY BY A WRIST-WORN ACCELEROMETER EQUIPMENT IN ELDERLY PERSONS. Aoki M^1,4, Kitabatake Y², Morozumi K¹, Egawa K², Nishiya T¹, Sugimoto A¹, Fujiwara T^3,4, Yamamoto I⁴; ¹Hachioji Health Cooperative Shiroyama Hospital. ²Physical Fitness Research Institute, Meiji Yasuda Life Foundation of Health and Welfare. ³Research Institute of Health Science and Education. ⁴Shinshu University

PURPOSE: The purpose of this study was to investigate the validation of elderly physical activity assessment methods using the wrist-worn equipment (Microstone Inc. model ViM ver.2.1.0: WTA). RELEVANCE: We examined the validity of assessment of physical activity with WTA by comparing energy expenditure as measured by WTA, also measured by a conventional hip-wearing accelerometer (Suzuken Inc. model Lifecorder: HTA) as compared to expiratory gas analysis as a standard, testing 27 healthy young male subjects. The result of free style walking treadmill testing showed high correlation of WTA and HTA results with the expiratory gas analysis. PARTICIPANTS: 16 elderly subjects (ages 60-70 yrs) without history of heart disease, orthopedics disease or physical disability participated in this study. We obtained the informed consent from all of subjects (in accordance with the ethical standards for human medical studies laid down in Declaration of Helsinki). METHODS: The subjects wore mask for the expiratory gas analytical instrument (Minato Medical Science Study, Inc. model AE-280), WTA on the right wrist, and HTA on the left hip. Protocol of this experiment was: 9 min. of sitting at rest. Then subjects walked at free style on the treadmill at speed of 2.4 km/hr and increasing to 3.6, 4.8, 6.0 km/hr for each 3 min. on treadmill, with no rest. ANALYSIS: Pearson’s correlation analysis, at significant level under 5%, was used. In addition, the Bland-Altman-plot was developed. RESULTS: There were significant correlations measuring energy expenditure with expiratory gas analytical instrument and WTA, HTA (WTA: r = 0.81, p < 0.01, HTA: r = 0.82, p < 0.01). In Bland-Altman-plot, the graphs of both WTA and HTA vs. expiratory gas analysis were distributed over the range that was approximately equal, with small deviation above and below, around the X-axis. CONCLUSIONS: The correlation coefficience of WTA measurements with that of expiratory gas analysis was significantly high. The high validity was demonstrated by WTA energy expenditure measurement distribution on the Bland-Altman-plot being approximately equal with a small range above and below, around the X-axis. The human gait is variable, and the gait of the elderly in particular is varied due to a much difference in physical ability. However, we demonstrated the possibility that WTA could be used to measure energy expenditure of the elderly. The validity of the energy expenditure that HTA calculates is reported in a previous study. The result of using WTA for physical activity analysis in this experiment was similar to results using HTA. IMPLICATIONS: As result of our study, both WTA and HTA are useful for measuring physical activity in elderly persons. And we may use them by a difference of ability for physical activity. KEYWORDS: physical activity, expiratory gas analysis, accelerometer. FUNDING ACKNOWLEDGEMENTS: We didn’t submit any outside funding for this study. CONTACT: aokichi@hachisei.or.jp

ETHICS COMMITTEE: Shiroyama Hospital Ethical Review Board