The influence of inspiratory muscle training on balance and functional mobility in healthy older adults
Study Design. Pilot Study
Objectives. Evaluate the effect of inspiratory muscle training (IMT) on balance and functional mobility in healthy older adults.
Background. Phasic diaphragmatic contractions are imposed upon respiratory activation to compensate reactive forces acting on the spinal column during upper limbs’ movements (Hodges and Gandevia 2000) but when respiratory demands increase (Hodges et al. 2001) or if inspiratory muscles are fatigued (Janssens et al. 2010), the diaphragmatic postural activity diminished. IMT facilitate the involvement of trunk in postural control in individuals with low back pain (Janssens et al. 2015). Therefore we hypothesise that IMT may also improve postural control in people with impaired balance.
Methods. Thirty-three participants, over 65 years performed eight weeks of IMT twice daily at 55% of their maximal inspiratory pressure. At baseline and after intervention lungs functions were evaluated by standard spirometry assessments; respiratory muscle strength by maximal inspiratory/expiratory pressures tests; balance by Mini-Best test; functional mobility by sit-to-stand-to-sit and functional reach assessments; back muscles endurance by sit-up and Biering-Sørensen tests; trunk muscles strength by recording isometric and dynamic contraction on dynamometer; questionnaires were used to classify fear of falling and daily physical activities.
Results. There were significant increments (P<0.001) in inspiratory muscle strength measured with peak inspiratory flow that increased by 12±1.2% and maximal inspiratory pressure that improved by 30±25%. Increments in balance measured with the Mini-Best test of 14±3.9% in particular in reactive (38%) and dynamic (14%) tasks. Back muscles endurance improved as showed with the Biering-Sørensen test by 68±30%.
Conclusions. Findings support the hypothesis that IMT improves balance and functional mobility in healthy older adults and provide justification for progressing the research to a randomised, placebo-controlled design.