Comparison of respiratory muscle training methods in individuals with motor and sensory complete tetraplegia: a randomized controlled trial

Abstract

OBJECTIVE: To compare the effects of inspiratory resistance training and isocapnic hyperpnoea vs incentive spirometry (placebo) on respiratory function, voice, thorax mobility and quality of life in individuals with tetraplegia. DESIGN: Randomized controlled trial. PATIENTS/METHODS: A total of 24 individuals with traumatic, complete tetraplegia (C5-C8, American Spinal Injury Association (ASIA) Impairment Scale; AIS A) were randomly assigned to 1 of 3 groups. They completed 32 supervised training sessions over a period of 8 weeks. Before and after the training period, the following tests were performed: body plethysmography, inspiratory and expiratory muscle strength, subjective breathing parameters using a visual analogue scale, voice measurements, thorax mobility and quality of life. Cohen's effect sizes and Kruskal-Wallis tests for differences between pre- and post-training values were calculated. RESULTS: Compared with placebo training, inspiratory resistance training showed high effect sizes for inspiratory muscle strength (d = 1.13), the subjective ability "to blow one's nose" (d = 0.97) and the physical component of quality of life (d = 0.82). Isocapnic hyperpnoea compared with placebo showed a high effect size for breathlessness during exercise (d = 0.81). We found a significant effect of inspiratory resistance training vs placebo (p = 0.016) and vs isocapnic hyperpnoea (p = 0.012) for inspiratory muscle strength. CONCLUSION: In individuals with motor and sensory complete tetraplegia during the first year post-injury, inspiratory resistance training is more advantageous than isocapnic hyperpnoea, performed 4 times a week for 10 min.