WTORS Glossary – Wheelchair Transportation Terms Explained
This WTORS glossary explains the key terms used in wheelchair transportation, securement, occupant restraint and vehicle restraint geometry.
WTORS
Wheelchair Tiedown and Occupant Restraint System. The overall system used to secure the wheelchair to the vehicle and restrain the wheelchair-seated occupant.
Wheelchair securement
The equipment and method used to control the wheelchair relative to the vehicle. This can include four-point tiedowns or a compatible docking system.
Occupant restraint
The restraint system used to control the passenger relative to the vehicle, typically including pelvic and upper-torso restraint components.
Four-point tiedown
A wheelchair securement system using four vehicle-to-wheelchair connections, usually two toward the front and two toward the rear.
Docking system
A mechanical wheelchair securement system using a compatible wheelchair-side interface and vehicle-mounted docking base.
Pelvic restraint
The lower portion of the occupant restraint intended to act on the occupant’s pelvic region.
Upper-torso restraint
The shoulder-belt portion of the occupant restraint that passes over the shoulder and across the chest.
Upper shoulder-belt anchorage
The upper vehicle-side anchorage that controls the direction and geometry of the shoulder portion of the occupant restraint.
WC18
Common shorthand for RESNA WC-4 Section 18, which addresses wheelchair tiedown and occupant-restraint systems.
WC19
Common shorthand for the RESNA wheelchair transportation section addressing wheelchairs intended for use as seats in motor vehicles.
MASOR
Mobility Aid Securement and Occupant Restraint. Terminology used in the Canadian standards context, including CSA Z605.
Transport-ready wheelchair
A wheelchair designed with motor-vehicle transportation use in mind and supported by relevant transport information, features and testing.
Postural belt
A belt used primarily for posture or positioning. It should not automatically be treated as a vehicle crash occupant restraint.
Vehicle anchorage
A structural attachment point used by wheelchair securement or occupant-restraint equipment.
Restraint geometry
The spatial relationship between the occupant, wheelchair and vehicle restraint anchorages that determines the resulting belt path.
What is WTORS? | Wheelchair Restraint Calculator | Standards Comparison
Content status: Updated by the Estraints Technical Team on 24 September 2026. See how Estraints develops and reviews technical guidance.