This article is reprinted with permission from the American Occupational Therapy Association. It was published in June 1999 in OT Practice and if it is referenced in a presentation or article should be cited as: Snell, M. A. (1999). Guidelines For Safely Transporting Wheelchair Users. OT Practice. 4(5) 35-38.
Injury can occur when the person hits something, something hits the person, or the person is ejected from the vehicle (2). At an impact speed of 30 miles per hour, the front of a vehicle comes to a complete stop within one tenth of a second, but unrestrained occupants and objects (e.g., purses, dogs, books, crutches, etc.) continue to move like projectiles toward the point of the crash impact at 30 miles per hour (2).
To calculate the pounds of forward force generated in a sudden stop or crash situation, multiply the weight of the object in pounds times the speed in miles per hour using Newton's Law of Motion (force = mass x acceleration or deceleration). For example:
As illustrated by Newton's Law of Motion, restraint systems, whether they are vehicle seat belts or children's car seats, are essential to protect the occupant in the event of a crash.
It is necessary to consider and understand the basic principles of crash protection and dynamic crash testing of commercial devices (e.g., vehicle seat belts, infant or child restraint systems) before preparing children and adults for transportation in their wheelchairs. The manufacture and use of vehicle seat belts and child restraint systems are legislated and standardized. No such standards exist for wheelchairs, even when they are used during vehicular transportation (1). ANSI-RESNA (American National Standards Institute - Rehabilitation Engineering and Assistive Technology Society of North America) (3) is developing standards for both tie-down devices and wheelchairs, but they must be passed into law before being enforceable. (Learn more about Wheelchair and Seating Standards in regards to Transportation in the WheelchairNet site).
A crash protection system could be a child's car seat, the vehicle's seat belt, or the wheelchair tie-down system in a van. Before the best safety decisions can be made, the following principles and requirements need to be emphasized.
PRINCIPLES OF CRASH PROTECTION
1. The crash forces must be dissipated.
2. Crash protection systems prevent the impact of the occupant with the interior of the vehicle.
3. Crash protection systems prevent the ejection of the occupant from the vehicle.
REQUIREMENTS DURING DYNAMIC TESTING
When a protection device is crash tested, it must remain in the same position if it is adjustable, not collapse, retain the test dummy within the confines of the device, and limit forward and rearward head excursion.
In short, the protection system needs to keep the occupant safe. These principles should be used to develop the safest possible guidelines for wheelchair or mobility device transportation.
There are two aspects to the safe transport of persons in a wheelchair: the wheelchair with its seating system and the vehicle tie-down system. Both are equally important, and one never compensates for a lack of the other
ANSI-RESNA (3) and the Canadian Standards Association (4 ,5) have been developing guidelines and standards for transportable mobility devices and tie-down systems. Sunrise Medical, Freedom Designs, and Invacare have tested their mobility bases with seating inserts and crash test dummies. The product tests conducted by these manufacturers used both wheelchair tie-downs and an occupant restraint system to secure the wheelchair and crash test dummy. It is hoped that more wheelchair and seating manufacturers will test their products and that all the manufacturers will continue to develop safer mobility bases, seating systems, and hardware for transportation.
The following guidelines for wheelchairs, seating systems, and vehicle tie-down systems were developed by the occupational therapists and physiotherapists at South Fraser Child Development Centre in Surrey, British Columbia, Canada. Each guideline was considered by using crash protection principles, requirements during dynamic testing of restraint systems, a literature review, and a review of guidelines and rationales established by other agencies. Decisions regarding transportation, including wheelchair seating and accessories and vehicle tie-down systems, are made with the family or caregiver, client, occupational therapist, physiotherapist, and rehabilitation equipment dealer. All equipment prescribed is accompanied by an explanation and a demonstration of its use and rationale. This is especially important for equipment that is prescribed for transportation reasons only.
Encourage the use of a child restraint system (car seat) for as long as possible before transporting a child in a wheelchair. Forty pounds is the maximum weight limit for most commercial forward-facing child restraint systems, and at this weight limit, children then switch to a booster seat. However, when more postural control and support are required, there are excellent restraint systems on the market for adults and for children who weigh more than 40 pounds. After the decision to be transported in a wheelchair is made, the following areas need to be considered.
The wheelchair should be equipped with an automobile-type of seat belt that fits snugly over the bony structure of the pelvis, not, over the abdomen. Chest harnesses, pommels, and other positioning aids are not substitutes for a seat belt but can be used with the seat belt for added truck support and positioning. The seat belt must be firmly attached to the wheelchair frame and not to the insert or to removable parts of the wheelchair frame (e.g., armrests). Triangular anchor end fittings and slides eliminate the need to punch holes in the seat belt ends in order to mount the belt to the frame. They also allow for easy size adjustment without having to punch additional holes in the belt, which would further weaken the webbing (6).
Modifying Wheelchair Frames
Do not modify a wheelchair frame (e.g., drill holes, cut bars, weld additional pieces) without consulting the manufacturer because this will likely void the manufacturer's warranty as well as create potential weak points in the frame.
Seating Insert Attachments
Ensure that the seating insert is well secured to the frame of the wheelchair at the back and base by using antigravity clips. Metal clips are usually recommended because the inherent strength of metal products leads to the assumption that they would perform better than plastic. However, crash comparison data of metal versus plastic anchors is not available. Hook-and-loop fasteners, webbing, or buckle systems are not recommended to anchor the system to the wheelchair frame because they are less likely than antigravity clips to hold the seating system in place during a crash. When the seating system does not have to be removed from the mobility base, the seating unit should be permanently attached to its frame.
The wheelchair user's head and neck should be protected from whiplash; therefore, a headrest is recommended for all wheelchairs and mobility devices as well as for standard upholstered wheelchair backs. For those who do not need a headrest-positioning device, the headrest could be used during transportation only. The headrest must be positioned accurately to provide protection. Vehicle headrest adjustments require it to be less than 1 inch from the back of the head, and for the middle of the headrest to be in line with the middle of the ears (7).
Head Bands and Restraints
The head should not be restrained during transportation because this leaves the neck unprotected. Alternate solutions for persons requiring upper thoracic, neck, and head positioning (e.g., a halo-style device) could include a well-fitting chest harness, foam lap tray, or soft neck collar.
Do not transport someone with the lap tray on the wheelchair. Lap trays were not designed to spread crash forces. In the event of a crash, a lap tray could cause severe abdominal injuries or become a flying missile and injure someone else. Alternatives for positioning include using a foam tray or soft neck collar.
Tilt-in-Space or Recline
Do not transport someone with the wheelchair in a tilted or reclined position; be sure that it (the wheelchair) is upright. In a crash situation, a tilted wheelchair changes the body's center of gravity, which increases the torso load of the seat belts and potentially can alter their position. Because the casters and front edge of the wheelchair seat are the weakest points and sustain high forces in a forward crash, the collapse and downward compression of the front end of the wheelchair opens the seat-to-back angle of the frame. If the wheelchair seat is tilted up, it increases the amount by which the seat-to-back angle could potentially open. The wheelchair user would then be in danger of sliding down and under the seat belt (8).
Special Medical Conditions
Ensure that wheelchair users who have shunts, G-tubes, tracheotomies, or sensitive areas are not under pressure or friction in these areas from the seating and positioning straps or from the shoulder or lap portion of the vehicle tie-down system.
Gel electrolyte batteries are recommended for power mobility units because they are sealed. Acid lead batteries could leak or spill if tipped. Batteries are very heavy and only minimally secured to the wheelchair frame, usually in a plastic shroud secured with a webbing strap.
The anti-tippers at the back of the wheelchair are designed to increase stability and prevent the wheelchair from tipping over (with normal use). They should be in the down position during transport. Although it is unlikely that they would hold in a crash situation, they do add stability during normal driving starts, stops, and turns.
Rigid Positioning Devices
Rigid positioning devices can be useful components for postural control. However, they should not be used during transport because they do not dissipate crash forces.
VEHICLE TIE-DOWN SYSTEMS
Never transport a person in a wheelchair without a restraint system. A tie-down system with an occupant restraint as well as wheelchair anchorage provides the best protection. Most companies now produce shoulder and lap belt systems for the occupant in addition to the four-point wheelchair restraint system. With this system, the wall and floor of the vehicle absorb the crash forces instead of the occupant of the wheelchair. If a wheelchair tie-down were used without an occupant restraint system, the person would have to rely solely on the belts and restraints attached to the wheelchair. Seating and positioning aids do not qualify as automobile restraints. However, in practice, there are still many commercial and private vehicles that have wheelchair tie-downs only without an occupant restraint component.
Homemade solutions may appear sturdy, but most would probably fail under crash conditions. Never recommend, construct, or use homemade anchor systems.
(Sitting so that the wheelchair is) rear facing is the safest direction for transport because most crashes are frontal, and the impact sends the body into the support of the surface behind the occupant. This is the rationale behind rear-facing infant restraint systems. However, front-facing transportation is recommended for the comfort of the traveler and because if the appropriate restraint system is in place, it is almost as safe as rear facing. Never transport someone in a side-facing position. Not only is it exhausting to the rider, but it is also the most dangerous position because it offers the least amount of protection from crash forces.
Any items that must be carried in a vehicle should be tied down firmly. Do not use bungee cords or other elasticized materials because they could snap in a crash. Protruding and loose objects can be tossed about in a crash and become deadly missiles for all occupants.
There are many issues for occupational therapists (and those responsible for safe transportation) to consider when recommending equipment and accessories to be used while transporting persons who use wheelchairs. Best practice indicates educating all stakeholders, especially the family and client, so they can make informed decisions. Wheelchairs and positioning accessories often come with labels indicating that they are not designed to be used as automotive restraints. However, many of the positioning accessories, such as four-point seat belts, chest harnesses, and headrests, can provide additional support to the vehicles tie-down and occupant restraint systems. Is using nothing (e.g., no headrest) better than using an accessory not recommended for automotive protection? This is a dilemma that will be argued until government standards are in place. Although much of this article has focused on crash situations, most of our clients require support and protection during "normal" driving because of impaired muscular function or reduced spinal-muscular stability, which is required to use the standard vehicle shoulder lap belt system. When working with clients on driving and transportation goals, occupational therapists should consider the following:
Mary-Ann Snell, OT(C), has specialized in pediatric practice of Occupational Therapy for more than 25 years. Foremost among her areas of interest are the evaluation and recommendation of seating and mobility equipment and the safe transportation of children with physical disabilities. She is currently the director of occupational therapy at South Fraser Child Development Centre in Surrey, British Columbia, Canada, and a member of the Pacific Infant Child Restraint Advisory Committee (PICRAC).
1. Americans With Disabilities Act of 1990. Public Law 101-336, 42 U.S.C. § 12101.
2. Transport Canada. (1994). Occupant restraints and the human collision. Ottawa, Ontario: Author
3. ANSI/RESNA. (in press). Wheelchair standards parts 1-16. Arlington, VA: RESNA Press.
4. CAN/GSA. (1995). Z604 Transportable mobility aids. Rexdale, Ontario: Author.
5. CAN/GSA. (1995). Z605 Mobility aid securement and occupant restraint systems for motor vehicles. Rexdale, Ontario: Author.
6. Axelson, P, & Chesney, D. (1995). Potential hazards of wheelchair lap belts. Proceedings of the RESNA '95 Conference, 15, 314-316.
7. Paskoff, G. R. (1995). Whiplash injury risk to people with disabilities travelling in wheelchairs. Proceedings of the RESNA '95 Conference, 15, 72-74.
8. Kang, G., Shaw, G., Pilkey, W, & Thacker, J. (1995). Crash response of wheelchair occupants with different sitting postures in transport. Proceedings of the RESNA '95 Conference, 15, 305-310.
FOR MORE INFORMATION ABOUT THIS TOPIC:
The Effects of Shoulder Belt Anchor Position on Wheelchair Transportation Safety. By G. E. Bertocci, 1995. Proceedings of the RESNA '95 Conference, 15, 311-313.
Fitting Motor Vehicle Shoulder Belts to Wheelchair Occupants. By K. Digges & D. A. Hobson, 1994. Technical Report #1. Pittsburgh, PA: University of Pittsburgh.
National Standards for School Transportation: Recommendations of the 12th National Conference on School Transportation. By the Missouri Safety Center, 1995. Warrensburg, MD: Central Missouri State University.
Occupational Therapy and the Americans With Disabilities Act (ADA) (Position Paper). By the American Occupational Therapy Association, 1993. American Journal of Occupational Therapy 47, 1083-1084.
The Safe Transport of Persons in Wheelchairs. By M. Snell, 1996. 12th International Seating Symposium Proceedings, 111-113.
Safety Resource Manual. By the National Highway Traffic Safety Administration, 1991. Washington, DC: Government Printing Office.
Securement of Wheelchairs in Motor Vehicles: Is it Time for a Universal Solution? By D. A. Hobson, 1995. Proceedings of the RESNA '95 Conference, 15, 87-89.
Transporting Children With Special Needs: Research and Resources Manual. By M. Bull, K. Stroup, & J. Doll, 1991. Indianapolis, IN: Automotive Safety for Children Program.
Universal Tie-Down and Occupant Restraint System for Mobility Aids. By C. A. McLaurin & G. Shaw, 1995. Proceedings of the RESNA '95 Conference, 15, 78-80.
Vehicular Transport Safety for the Child With Disabilities. By G. Shaw, 1987. American Journal of Occupational Therapy, 41, 35-42.
Wheelchair Crash Structural Computer Model. By G. S. Dupuis, W. Pilkey, J. Thacker, & W. Kang, 1995. Proceedings of the RESNA '95 Conference, 15, 306-307.
Wheelchair Transport Standards: What Are They All About? By D. A. Hobson, 1996. 12th International Seating Symposium Proceedings, 105-109.
Homepage for Wheelchair Transportation Standards
Homepage for RESNA where some RESNA conference proceeding are published.
Last Updated: 3-2-2006