Biomechanical analysis of different dynamic sitting techniques: an exploratory study

Prolonged static sitting in wheelchairs increases the risk of pressure ulcers. This exploratory study proposed three dynamic sitting techniques in order to reduce the risk of developing pressure ulcer during wheelchair sitting, namely lumbar prominent dynamic sitting, femur upward dynamic sitting, and lumbar prominent with femur upward dynamic sitting. The purpose of this study was to analyze the biomechanical effects of these three techniques on interface pressure. 15 able-bodied people were recruited as subjects to compare the aforementioned sitting techniques in a random order. All parameters, including dynamic contact area, dynamic average pressure, and dynamic peak pressure on backrest and seat were measured and compared. In result, when compared with lumbar prominent dynamic sitting, femur upward dynamic sitting and lumbar prominent with femur upward dynamic sitting appeared to yield significantly lower dynamic average and peak pressure on the back part of seat, and significantly higher dynamic average and peak pressure on the front part of seat. This study can serve as a reference point for clinical physicians or wheelchair users to identify a suitable dynamic sitting technique.