Effects of intermittent electrical stimulation on superficial pressure, tissue oxygenation, and discomfort levels for the prevention of deep tissue injury.

The overall goal of this project is to develop effective methods for the prevention of deep tissue injury (DTI). DTI is a severe type of pressure ulcer that originates at deep bone-muscle interfaces as a result of the prolonged compression of tissue. It afflicts individuals with reduced mobility and sensation, particularly those with spinal cord injury. We previously proposed using a novel electrical stimulation paradigm called intermittent electrical stimulation (IES) for the prophylactic prevention of DTI. IES-induced contractions mimic the natural repositioning performed by intact individuals, who subconsciously reposition themselves as a result of discomfort due to prolonged sitting. In this study, we investigated the effectiveness of various IES paradigms in reducing pressure around the ischial tuberosities, increasing tissue oxygenation throughout the gluteus muscles, and reducing sitting discomfort in able-bodied volunteers. The results were compared to the effects of voluntary muscle contractions and conventional pressure relief maneuvers (wheelchair push-ups). IES significantly reduced pressure around the tuberosities, produced significant and long-lasting elevations in tissue oxygenation, and significantly reduced discomfort produced by prolonged sitting. IES performed as well or better than both voluntary contractions and chair push-ups. The results suggest that IES may be an effective means for the prevention of DTI.