Development of a wheelchair headrest for rear impact protection

Evaluation of wheelchair headrests in the 1990s showed that commercially available products failed in static FMVSS 202 tests. However, those tests did not evaluate dynamic rear impact neck injury risk for wheelchair users. In this paper baseline testing of the BIORID dummy seated in a surrogate wheelchair subject to IIWPG rear impact tests is presented. Neck hyperextension was observed, and injury risk evaluated using the NIC and Nkm criteria showed significant risk for occupants of rigid wheelchairs with no headrest in rear impact. A prototype neck protection headrest was designed and tested and results showed that the device successfully prevented hyperextension of the neck, and large reductions in the injury scores evaluated using the NIC and Nkm criteria were observed.