Pressure injuries are a common secondary complication following spinal cord injury (SCI). Since individuals with SCI have sensorimotor impairments, they neither can feel pain associated with tissue damage due to prolonged unrelieved pressure nor are able to prevent pressure injuries due to mobility impairments. Deep tissue injury is a form of pressure injuries that occurs in the muscle and subcutaneous tissue before tissue breakdown appears at the skin surface.

This thesis attempted to address four research questions pertinent to deep tissue injury and offloading in individuals with SCI. First, we proposed a quantitative ultrasound imaging approach to characterize the integrity of the tissues overlying the ischial tuberosity. We demonstrated that the thickness and gray scale measures of the skin, subcutaneous tissue and muscle has potential to be used as a tissue health monitoring approach.

The second study investigated our ability to assess trunk strength and function using the multidirectional reach test. This study demonstrated that monitoring changes in trunk strength and reach distance could be used to assess trunk function in individuals with SCI.

The third prospective cross-sectional study aimed at determining if there is a relationship between trunk function and offloading of the ischial tuberosities in individuals with SCI. We discovered that trunk strength was significantly higher in people who were able to Reach compared to Non-Reachers, and that offloading times over the ischial tuberosities were lower in Non-Reachers vs. Reachers. Regardless of an individual’s ability to engage in a reaching task, participants with SCI spent more time offloading the left ischial tuberosity compared to the right ischial tuberosity.

The fourth exploratory prospective cross-sectional study compared thickness and texture measures of tissue overlying the ischial region in able-bodied vs. SCI participants. We discovered that the area occupied by muscle was significantly greater in the SCI participants when compared with the able-bodied cohort. Individuals who did not engage in offloading had more homogenous skin, subcutaneous tissue and muscle.

These studies represent the first step towards better understanding the relationships between offloading, trunk function and health of tissue overlying the ischial tuberosity in SCI population.