Interested in disability history? Check out what happened Today in AT History!

Wheelchair tie downs

From ATWiki

Many wheelchair users who require transportation in a motor vehicle may not be able to transfer or be seated safely onto the provided seats of the vehicle. Personal automobiles, public transit buses/subways, and paratransit vehicles need to accommodate for the securement of wheelchairs and their occupants during motor vehicle transportation. Guidelines for wheelchair securement are provided by the Society of Automotive Engineers J2249 Wheelchair Tiedown and Occupant Restraint Systems (WTORS) Recommended Practice and through the International Standards Organization (ISO) 10542 Wheelchair Tiedowns and Occupant Restraints Standard. Some securement systems are side-facing while others are front-facing. Two basic categories of tie down systems include the manual tie down systems and the electric docking systems. Both these are front-facing wheelchair securement systems and are discussed in this article.

1 Manual Tie Down Systems
2 Electric Docking Systems
- 2.1 Pros
- 2.2 Cons
3 Product Links
4 External Links
5 References

Manual Tie Down Systems

Manual tie down systems consist of four straps at each corner of the wheelchair frame that secure the wheelchair to the floor of the motor vehicle. As such, they are usually referred to as four-point safety restraint systems or four-point strap-type tiedown systems.

Pros

Can accommodate different wheelchair types and sizes
Electrical failure is not a concern
Relatively cheaper than electric docking systems

Cons

Cannot be secured by the wheelchair user, requiring the aid of a caregiver
Components susceptible to loosening
Need to balance tension properly on all four corners
Need adequate space for installing anchorage points

Major components

Vehicle Floor Anchors

These components serve as anchorage points for attaching the track fittings on the straps/belts to the floor of the vehicle. Two main styles of floor anchors are fixed attachment points and rails.

Fixed attachment points are single receiving units for the straps that need to be fixed to the floor of the vehicle. Since they are only single points of attachment, they do not take up much space, but do not allow flexibility in changing the wheelchair position or accommodating different wheelchair designs.
Rails have multiple points of attachment for the straps. As such, the straps can be moved to accommodate different sized wheelchairs and different wheelchair positions. Because they are longer, they take up more space in the vehicle.

Straps/Belts

The tension in the straps/belts on all four corners secures the wheelchair from moving in the vehicle. This tension can be adjusted by changing the length of the straps/belts.

Strap Attachment Hardware

Strap attachment hardware latch onto the structural frame member of the wheelchair at the corners of the seat cushion. The attachments should never be hooked onto the wheels or any other removable portion of the wheelchair for safety reasons. Instead, they should be attached to the specific securement points provided by the wheelchair. If there are no indicated securement points, the strap attachments are best secured to the welded junctions of the structural wheelchair frame that are as close to the seat surface as possible.

Different attachment designs are available on the market including the following:

S hooks
Buckle and buckle connectors
Snap hooks and D-ring
Wire hook and ring

Tension Mechanism

The tension mechanism allows adjustment to the length of the strap/belt so that the tension can be increased or decreased. Some mechanisms are manual while others are self-retracting. The following lists a few designs currently available:

Automatic retractors
Overcenter buckles
Ratchet systems
Cam systems

General Safety Tips

Do not bend straps around wheels (straps should follow a straight path)
Do not mix different strap buckles
Do not cross connect straps
Keep straps away from sharp edges
Ensure straps are in good condition

Electric Docking Systems

These systems allow wheelchair users to secure their wheelchairs independently. As such, they can accommodate those who wish to drive while seated in their wheelchair. Rather than having straps tethered to the floor, these electronic systems consist of a docking interface that accepts a bracket installed on the underside of a wheelchair. Once the wheelchair is positioned properly, the docking interface locks automatically and secures the wheelchair. The wheelchair can be unlocked through the push of a button. These systems usually have a manual release feature in the event of electrical failure. It is also advised to have a backup battery for the docking system.

Pros

Wheelchair occupant can secure chair independently
Much faster and easier than manual systems

Cons

More expensive than manual tie down systems
Not recommended for those who are dependent on a caregiver
A bracket fixture needs to be installed to the underside of the wheelchair and depending on the design, may not accommodate for varying sizes and types of wheelchairs
Fixed location for docking
Dependent on a power source