Sitting Pressure in a Wheelchair With Adjustable Ischial and Back Supports
By Makhsous, M.; Patel, J.; Lin, F.,; Hendrix, R.W.; Zhang, L.; RESNA 26th International Annual Conference 2003,Publication Date: 2003
Study conducted to investigate pressure changes in a wheelchair seat design characterized by unloading the ischia (hip joint) and supporting the lumbar spine in order to decrease the risk for pressure sores. The back part of the wheelchair seat was tilted downward to decrease the pressure under the ischia while shifting the contact area toward the thighs. Additional lumbar support was also added to the backrest. Six people who used wheelchairs participated in the study, while ten office workers with no history of musculoskeletal disabilities served as a control group. An X2TM wheelchair was used for the control group. A ROHO cushion was used with the seating system, and an Xsensor pressure-mapping device was used to measure pressure distributions on both the seat and backrest. The total contact area, peak pressure, average pressure, and center of pressure were calculated. Knee extension was measured with an Optotrak motion capturing system from Northern Digital, Incorporated. Interface pressure was measured during static sitting and sitting with slow voluntary knee flexion/extension. Four trials were carried out for each condition. Results indicated that significant changes in contact area were induced when lumbar support was added and when ishcial support was removed. The authors contend that this demonstrates the effectiveness of the new wheelchair mechanism in lowering contact on the spine and redistributing the support to other regions, therefore reducing the risk for pressure ulcers.
Published by: Rehabilitation Engineering & Assistive Technology Society of North America (RESNA) (Website:http://www.resna.org)
