Abstract
Respiratory musculature is negatively impacted after a spinal cord injury (SCI) likely affecting both breathing and balance function. A neurological change in input to the muscles of respiration and a physical change in breathing biomechanics are likely the cause of pulmonary complications and partially accounts for the consistently high respiratory related mortality rate. Current standard direct and indirect respiratory assessments do not appear to accurately distinguish individuals with respiratory muscle weakness or individuals at risk of pulmonary compromise, based on the high mortality rate. As such, it is important to investigate alternate measures relating to respiratory function that may better assess breathing performance of individuals with SCI.
SCI-appropriate respiratory assessments may allow for a more specific investigation into the relationship of respiratory muscle strength and seated balance in individuals with SCI. Currently, evidence of a dual role of the diaphragm exists only for neurologically intact individuals. It is unknown whether this relationship persists after SCI. To investigate the relationship between respiratory function and balance it is critical to have SCI-specific measures of both constructs. However, there is currently no gold standard assessment for seated balance to be used with individuals with SCI. If respiratory muscle performance and balance are related in SCI, respiratory musculature training could be a novel intervention targeted for balance recovery.
Training respiratory musculature is not a novel concept in individuals with SCI and there is evidence that links various types respiratory muscle training (RMT) to improved breathing and decreased risk of pneumonia or respiratory compromise. However, it appears that there are barriers to implementing this evidence because respiratory related deaths still account for the highest percent of mortality in the SCI community. As such, the overarching goal of this work was to assess the feasibility and impact of a novel-to-SCI, high-intensity, home-based inspiratory muscle training program on both respiratory function and balance in people with chronic SCI using SCI-specific balance and respiratory assessments.