What is the basis for these WC19 wheelchair and WTORS standards?

The requirements and provisions of the RESNA Volume 4 standards are based on some fundamental principles of occupant protection. These include the following:

  1. The most common cause of serious and fatal injuries is occupant contact with vehicle interior components, or with objects outside of the vehicle following or during ejection.
  2. The majority of serious injury-producing crashes occur during frontal impact, or when the principal direction of vehicle deceleration is in the direction of vehicle travel, or toward the front of the vehicle.
  3. Effective occupant protection requires effective occupant restraint by a belt-type restraint system that includes a lower-torso or pelvic/lap belt and an upper-torso shoulder belt or harness.
  4. Restraint belts must be positioned so that the forces applied to the occupant in a crash are primarily to the skeletal structures of the shoulders and pelvis.
  5. Effective occupant restraint requires that the vehicle seat is effectively secured in the vehicle seat and that it has sufficient strength to support the occupant in a seated posture during impact. These are necessary to prevent the mass of the seat from transferring to the occupant in a crash, and to enable the belt restraints to remain in their preferred locations on the pelvis and shoulders.

In addition to these fundamental principles of occupant crash protection, these standards are based on provisions, requirements, and methods in current federal safety standards, such as FMVSS 213 Child Restraint Systems and FMVSS 209 Seat Belt Assemblies. The standards are also based on a desire to minimize the costs involved in testing to the standards.