The effects of the predictability of an arm reaching target on seated postural stability, reaching time and selected minimum data set for nursing home residents

Objectives: (1) to examine the effects of the predictability of a reaching target on postural stability and reaching time; (2) to determine the relationship of postural stability with cognitive decision-making and the ability to walk. Methods: An electromechanical system measured body stability and reaching time of 38 nursing home residents ≥ 75 years old during a reaching task. Comparisons between predictability, reaching time, cognitive and walking skills were examined using ANOVA's statistical procedures. Effect sizes were calculated to determine the strength of the relationships. A Sidak statistical adjustment was used to minimize possible errors from multiple statistical tests. Results: Participants showed significant differences between their reaching time and walking ability (p < .01), between their cognitive ability and seated postural stability (p < .021), and between their walking ability and seated postural stability (p < .022) in the unpredictable condition. The findings do not support the hierarchical postural control evaluation and treatment model traditionally used in the clinic. The clinical implication of this study is that predictable and variable practices may be used simultaneously, not sequentially, in the rehabilitation of older adults. These results illustrate the complexity and the non-hierarchical relationship of reaching predictability, cognitive and walking skills, and postural stability. Research on the relationship of environmental predictability and its effect on postural stability, as well as the exploration of the relationship of postural stability with cognitive decision-making and the ability to walk in nursing home residents, is warranted to expand the understanding of seated postural control in older adults.