| Description |
This thesis aims to measure the difference in sea ted normal and shear stresses based upon different types of wheelchair propulsion types. Previous studies have measured biomechanical influence of wheelchair propulsion a t the upper extremities. This study intends to measure the biomechanical differences a t the seating surface where wheelchair users are vulnerable to deep tissue and skin breakdowns. Pressure ulcers have been studied to form based upon a number of factors, specifically: too much pressure, friction, shear, and heat /moisture buildup. However, very little research has been performed measuring seating stresses in vivo based upon wheelchair propulsion. Multiple metrics w ere used to measure the normal and shear stresses in 10 ambulatory subjects (5 male and 5 female). To measure normal pressure, pressure mapping w as used. To measure the shear stresses, a Molten Perdie was used to measure shear. Two dramatically different wheelchair cushions w ere used: an air adjustable cushion and an HR-42 Foam block of similar size. Two different types of manual wheelchair propulsion w ere used: the traditional hand-rim wheelchair and the developmental lever-arm wheelchair. It was hypothesized that the combination of the lever-arm wheelchair and the pro p e rly adjusted air cushion would significantly reduce the normal pressure and shear stresses associated with chair propulsion. The data showed a significant difference for the normal pressure for 9 of the 10 subjects in favor of the air cushion over the foam cushion. However, the shear data did not show a significant difference for a reduction of shear for any configuration of testing. |
