Respiratory strength training: concept and intervention outcomes.

Respiratory muscle strength training (RMST) focuses on increasing the force-generating capacity of the inspiratory and expiratory muscles. The choice of respiratory muscles that are targeted using RMST depends on the outcome desired. For example, if an individual has reduced inspiratory muscle strength due to a neurogenic injury and is unable to ventilate the lungs, then inspiratory muscle strength training may be the chosen rehabilitation target. On the other hand, if a professional voice user is complaining of difficulty generating adequate vocal loudness during song production and is suffering from laryngeal dysfunction, then an expiratory muscle strength training paradigm may be the chosen rehabilitation target. Our most recent work with RMST has focused on increasing expiratory muscle force generation for those with Parkinson's disease who have difficulty with breathing, swallowing, and cough production. This difficulty typically worsens as the disease progresses. Highlights of these outcomes are summarized in this article.