Development of test methodologies for determining the safety of wheelchair headrest systems during vehicle transport

For wheelchair users unable to transfer to a vehicle seat, the wheelchair serves as a means of mobility and postural support during activities of daily living and as a seating support in a vehicle. The performance of commercially available adaptive seating components in a dynamic or impact situation, as well as their effect on the safety of the user, is unknown and should be determined. The main objective of the project was to develop a test methodology to statically determine the crashworthiness of wheelchair headrest systems and show the efficacy of that methodology by applying it to several commercially available headrest systems. The methodology was based on Federal Motor Vehicle Safety Standard (FMVSS) test conditions, which use static test procedures to ensure that vehicle head restraints will perform adequately during actual crash conditions. The procedure developed to evaluate the headrests gave informative and repeatable results. The tests performed calculated the energy associated with a critical deformation of the headrest under quasi-static conditions. The results were used to determine the level of safety provided by the devices and to recommend design improvements. The headrests tested exhibited similar modes of deformation due to bending of a vertical adjustment bar, and several devices were determined to be capable of providing adequate restraint in an impact situation.