Effects of increased inspiratory demand on postural stability in the elderly

Abstract

Introduction: Aging can cause physiological and functional changes, and these, in turn, can lead to a decline in functions and functional capacity, and thus generate a compromise in autonomy and mobility, and increase the risk of falls. Aging is also associated with biological changes that compromise inspiratory muscle function. There are studies that have shown that all trunk muscles work together with the function of protecting the spine and preserving postural control, including the inspiratory muscles, however, the role of the diaphragm in breathing always takes precedence over postural function. Objective: To verify the influence of the increase in the inspiratory demand on the postural stability of the elderly, through a case study. Methods: Three elderly individuals initially performed the assessment of maximal inspiratory pressure (PImax), and then underwent a postural stability test. In the Biodex Balance System SD equipment, they performed the protocol of the device itself called 'Postural Stability Test' (PST), in order to evaluate the instability index in two different conditions. In the first condition, the elderly performed the test and could breathe normally, without exerting themselves and trying to keep themselves balanced on the equipment platform; in the second condition, the elderly were evaluated by breathing through the Power Breathe® equipment and using a nose clip. To achieve this condition of increase in inspiratory demand, an overload of 50% of the MIP value, evaluated at the beginning, was adopted. Results: In the anterior-posterior oscillations, all the elderly showed a higher index of instability in the test with increased inspiratory demand and for the right-left oscillations, two of the elderly evaluated presented a higher index of instability in this condition. Conclusion: The increase in inspiratory demand provided by the Power Breathe® device was able to change the balance of the elderly, increasing the postural instability of those evaluated. We consider that for more enlightening results it is necessary to carry out a randomized and controlled study with a larger sample.