The influence of inspiratory muscle training upon balance and functional performance with older adults.

Abstract

Accidental falls are the leading cause of fatal and non-fatal injuries amongst older adults in the Western world. Around 30% of people over 65 years will fall at least once a year in the UK, whereas 50% of people over 80 years will fall annually (NICE 2013). Recently, falls prevention programmes have begun to incorporate multidimensional movements with controlled breathing techniques (e.g. yoga, Tai chi and Pilates). Based on the research of Hodges, the diaphragm muscle may contribute to balance maintenance in two ways. Firstly, the diaphragm is activated during upper limb movements, which indicates that diaphragm co-activation may assist in the mechanical stabilisation of the spine. Secondly, the diaphragm plays a key role in the development of intra-abdominal pressure that helps to stabilise the lumbar spine during balance perturbations (e.g. shoulder abduction and adduction). This doctoral project investigates whether the effects of structured inspiratory muscle training (IMT) on respiratory function can improve indices of balance and physical performance with older adults. The project comprises three studies, each involved IMT delivered over 8 weeks, at home, and unsupervised. The IMT included: workload progression (increased according to each participant’s weekly improvement), twice-daily sessions (morning and evening) and training diaries (to monitor progression, adherence and attrition). Outcomes included: respiratory muscle function (e.g. maximal inspiratory pressure), physical performance (e.g. timed up and go), static and dynamic balance (e.g. mini-BEST) and trunk muscle strength (e.g. isometric flexion and extension) for a sample of older adults (n =129; age 72 ± 5 years). In study 1 IMT was found to be both feasible and safe, as an unsupervised home-based intervention with healthy older adults. In study 2 IMT proved to also be effective in improving respiratory muscle function, physical performance, dynamic balance and trunk muscle endurance. The final study (3) involved a comparison of community- dwellers performing IMT, and care home residents performing the Otago exercise programme (an established falls prevention intervention). Results showed that IMT produced similar balance improvements as the Otago exercise programme over 8 weeks, but with additional benefit to inspiratory muscle function and walking speed. In combination, these findings support the possibility of introducing IMT as a novel intervention for falls prevention for older adults in isolation, or together with established falls prevention intervention.