The Nintendo Wii Balance Board (WBB) has become popular as a low-cost alternative to research-grade force plates. The purposes of this study were to characterize a series of technical specifications for the WBB, to compare balance control metrics derived from time-varying center of pressure (COP) signals collected simultaneously from a WBB and a research-grade force plate, and to investigate the effects of battery life. Drift, linearity, hysteresis, mass accuracy, uniformity of response, and COP accuracy were assessed from a WBB. In addition, 6 participants completed an eyes-closed quiet standing task on the WBB (at 3 battery life levels) mounted on a force plate while sway was simultaneously measured by both systems. Characterization results were all associated with less than 1% error. R 2 values reflecting WBB sensor linearity were > .99. Known and measured COP differences were lowest at the center of the WBB and greatest at the corners. Between-device differences in quiet stance COP summary metrics were of limited clinical significance. Lastly, battery life did not affect WBB COP accuracy, but did influence 2 of 8 quiet stance WBB parameters. This study provides general support for the WBB as a low-cost alternative to research-grade force plates for quantifying COP movement during standing.
Tyler B. Weaver, Christine Ma and Andrew C. Laing
Robert H. Friis, Wendy L. Nomura, Christine X. Ma and James H. Swan
Walking for exercise might counteract the effects of a sedentary lifestyle. We examined the demographic and health-related predictors of walking 1 mile per week or more among the elderly. Data were from the 1984 Longitudinal Study of Aging. Participants were 7,527 adults age 70 years or older. Demographic factors related to walking were younger age, college-level education, being unmarried, and higher income. Health-related variables associated with walking included positive self-perception of health, internal health locus of control, and absence of activity limitations. The prevalence of regular walking for exercise was low in the study population (38% and 26% for men and women, respectively). Interventions that increase the internal health locus of control might be effective in increasing walking among the elderly.