What does WC19 say about head restraints and what should I do for rear-impact protection?
At the present time, WC19 is silent on rear head restraints for wheelchair occupants. Research and development projects have addressed this topic as well as wheelchair backrest performance in rear impacts. The primary issue and concern is neck injury in rear impact crashes. The head restraints provided in vehicles are specifically designed for this scenario, but the head supports on wheelchairs are meant to provide postural support and may not perform well in a crash. In some cases, the head support will break free of the wheelchair during a crash. While neck injury is an important concern, it is not nearly as large a concern as injuries in frontal crashes, especially in larger school buses. In the meantime, the use of wheelchair seating systems that have high backrests and that include some kind of padded rear head support will offer enhanced occupant protection, both during rebound in frontal crashes and in rear impacts.
While the typical wheelchair back support is likely to deform somewhat during rear-impact loading, this is probably a positive factor in most rear impacts, since the forces on the neck are reduced when there is some deformation of the back support. In this regard, it is important not to install a vehicle-anchored head support system without including additional vehicle-anchored support for the wheelchair back support, since a strong rear head restraint without strong back support could result in injurious loading to the neck in a rear impact. The primary challenge in providing effective rear head and back support using a vehicle-mounted system is achieving close positioning of the support surfaces to the backrest of the wheelchair and head of the occupant. This is not easily accomplished when a wheelchair space in a vehicle is used by a wide range of wheelchair users with different types and sizes of wheelchairs.