Injury risk assessment of wheelchair occupant restraint systems in a frontal crash: a case for integrated restraints

Obtaining proper occupant restraint fit when using a wheelchair as a motor vehicle seat is often difficult to attain with vehicle-mounted restraint systems. The comprehensive evaluation conducted in this study illustrates the occupant crash protection benefits of wheelchair-integrated restraint systems, as compared to vehicle-mounted restraint systems. Using computer crash simulation, occupant kinematic and biomechanical measures associated with a 20g/30mph frontal impact were evaluated and compared to injury criteria and SAE J2249 WTORS kinematic limits. These measures were also used to compile a Motion Criteria (MC) index and Combined Injury Criteria (CIC) index for each evaluated restraint scenario. These indices provide a composite method for comparing various crash scenarios. With the exception of an unsafe 36-inch height off-shoulder shoulder belt anchor scenario, the MC index was minimized for the integrated restraint scenario. Similarly, the CIC index was also minimized for the wheelchair-integrated restraint scenario. This preliminary study emphasizes the need for transfer of integrated restraint technology to the wheelchair transportation industry.