Background: Stroke results in varying physical, cognitive, emotional and/or social disabilities in the short and long term alike. Motor impairments are important, persistent consequences of stroke and include, among others, decreased respiratory muscle function, decreased ability to expand the thorax and postural dysfunction. These deficits affect the patient's ability to perform daily activities, produce fatigue and reduce endurance and quality of life. Inspiratory muscle training (IMT) aims to improve the strength and endurance of the diaphragm and the external intercostal muscles. The objective of this study was to investigate i) the effect of three weeks of IMT on maximal inspiratory pressure (MIP) in adults having suffered a stroke, and ii) the effects of three weeks of IMT on the degree of dependency in activities of daily living, endurance in gait, fatigue, voice volume, phonation endurance and expiratory function.
Methods/Design: This is a randomised controlled trial (RCT) comparing IMT with conventional neurorehabilitation (usual practise). The trial will include 80 patients with reduced MIP hospitalised at a specialised neurorehabilitation hospital in Denmark. The intervention group will receive IMT sessions, exercising at 30% of MIP. Patients in the intervention group will perform two daily sessions (one session of IMT with Threshold IMT consisting of two times 15 inspirations at normal breathing rhythm (5-10 min)), seven days a week for three weeks. Training can be with or without physiotherapist supervision. Study outcomes: MIP assessed by the Power Breath, Functional Independence Measurement, The 6-minute Walk Test, the Fatigue Severity Scale and average voice volume. Expiratory function will be assessed using spirometry. All assessments will be conducted at baseline and three weeks (at termination of the intervention) and three months after the intervention has concluded.
Discussion: The primary purpose of this study is to assess the effect of IMT interventions in patients with reduced MIP following stroke; secondarily, to assess the effect of IMT on the degree of dependency in activities of daily living, endurance in gait, fatigue, voice volume, phonation endurance and expiratory capacity. Hereby, this study accepts the call for further research.
Trial registration: ClinicalTrials.gov NCT04686019. Registered 28.12.2020, https://www.clinicaltrials.gov/ct2/show/NCT04686019