Special considerations must be taken to prevent common injuries.

Secondary complications (such as pressure ulcers, abrasions, pinch points, and orthopedic deformities), falls, restraints, and transportation are all safety issues for wheelchair users that clinicians must address.

One area of wheelchair seating that might not garner enough attention is safety. Wheelchair users can be made safer through the appropriate selection of equipment, proper training of the user and caregivers, and education about the risks associated with the equipment.

Maintaining Skin Integrity

The prevention of pressure ulcers should be a paramount consideration for all new wheelchair users with diminished sensation, cognition, and mobility. Many clinicians are comfortable selecting cushions to prevent pressure ulcers via pressure measurements, periodic skin checks, or a combination of the two. But skin-integrity problems can also occur due to improper use of the cushion (such as poor inflation or improper orientation) or its continued use after cushion fatigue. For these reasons, wheelchair users and their caregivers must be properly trained on the proper use of cushions and taught to check if the cushion is in good repair.

Abrasions, bruises, and pinch points can also lead to skin-integrity problems. Abrasions or bruises can occur when mechanical-lift slings are left in the chair, when trunk or head supports are poorly padded or poorly aligned, or when abductor pads are poorly padded or misused as restraints. Postural restraints and supports, such as lap trays, belts, chest straps, or ankle straps–and their buckles and fasteners—can rub or bruise the skin when they are used to restrain movement, so they should be properly padded and sized to distribute the load on the skin. Unpadded railings on the leg rests or poorly padded armrests can also lead to skin problems. Pinch points from swing-away or removable hardware should also be monitored.

Postural Alignment

Certain seating systems are designed to correct or accommodate postural asymmetries or to support postural instability. If they are improperly designed or fitted to the user, postural supports can promote poor alignment, which can lead to orthopedic deformities such as subluxed joints (hips, shoulders), contractures, or obliquities. A proper seating evaluation, during which orthopedic limitations and instabilities are identified, is the most effective way to properly select postural supports. Too often, wheelchair users are asked to adopt a posture that their bodies cannot attain, and an orthopedic deformity occurs as a result. Examples include sitting a person with a kyphosis in a flat back that can further flex the trunk while encouraging hyperextension of the neck, or the spinal deformities that result from not supporting an unstable trunk.

Preventing Falls

Falls during transfers are risks that can be influenced by the seating system. All components should remain stable while a person is moving during a transfer. A sliding cushion or a backrest that gives way can cause the wheelchair occupant to lose his or her balance. Add-on hardware, such as that used to secure drop seats and the backrest, is designed to be released to allow the components to be removed during wheelchair transport or stowage. This operation can alter the alignment of the add-on hardware, resulting in poor securement when the seat or back is reattached. Often, slight misalignment permits the seat or back to be attached and to appear secure. However, because it is not secure, the seat or back can release suddenly. Therefore, care must be taken to properly secure add-on hardware and to periodically check its attachment to seats and backs.

During assisted transfers, seating-system components can hinder the caregiver’s access to the wheelchair occupant. Poor access when helping the wheelchair occupant transfer not only puts the caregiver at risk but can cause the wheelchair occupant—who is not properly lifted or guarded—to fall. Hindered access might be due to a lateral support or headrest, or any component that prevents the caregiver from having good body alignment. New users and caregivers must be properly trained on transfer techniques and the operation of the seating-system components to ensure that this risk is reduced.

Improper securement of a cushion or postural support can also make the user slide or fall out of the chair. This risk is particularly present when the chair comes to an abrupt stop (such as when the wheelchair hits a high doorjamb) or traverses uneven terrain. The risk of a fall is also present in the inattentive wheelchair user who, while slowing, slips down or leans over in response to gravity. Both the wheelchair cushion and the user’s buttocks have a tendency to slide forward due to the body’s posture while sitting against a backrest. A reclining backrest or propelling with one’s feet significantly increase this tendency. In these cases, proper securement of the pelvis via a lap belt or slightly inclining the seat can provide the needed stability. Often, fall risks are minimized through the proper use of postural supports such as lap belts, chest belts, or harnesses. However, clinicians must be very cautious regarding the line between postural supports and physical restraints.

While insufficient securement or stability might contribute to a fall from a chair, improper securement can also be dangerous.

Restraints

For the purpose of this article, the term “postural restraint” will be used as a means to focus on supports that address postural alignment of the trunk, pelvis, and lower extremities. They are considered a subset of physical restraints, which are those that secure the extremities to prevent injury or wandering. They offer stability and proper body alignment so that users can function at their best, and they offer safety and securement when the users require restraint.

Postural restraints must be considered in every safety assessment, as they can contribute to severe injury or death. Most clinicians have heard of asphyxiation injuries or deaths from restraints used in wheelchairs and beds. However, since postural restraints are a component of many seating systems, clinicians should understand several aspects of restraint safety. The majority of asphyxiation deaths due to restraints occur when the restraints are properly applied.1 

Vest-type and lap-belt restraints are the most common restraints used in wheelchairs, and the vest-type restraint represents the highest risk. A loosely secured vest restraint that is attached to the backrest compresses the neck when the user slides down in the chair. Vest restraints might need to be loose to give the user some trunk mobility while preventing him or her from falling forward in the chair, so a tight vest restraint might hinder function.

A lap belt should always be used in conjunction with a vest restraint. A lap belt, securely fastened over the bony pelvis, will prevent the user from sliding forward in the seat, resulting in increased stability when seated and a reduced risk of injury from vest-type restraints. Belts work best when they are applied over the bony skeleton, because soft tissue deforms and deflects, thereby efficiently loosening the belt or changing the line of pull. But because belts work best over bone, they must be sized and padded properly to adequately distribute the load.

The belts’ line of pull is very important when determining their effectiveness; because belts work in tension, they can be considered to have a single line of force. Many clinicians consider different lines of pull in lap belts (45°, 60°, and 90°), depending on the belts’ intended effects. But line of pull must be considered in chest and lower-extremity belting. All belts (and all hardware in general) will loosen over time, so they must be checked regularly to ensure that they are operating properly. The more adjustable a device is—whether it is a headrest, trunk support, or pelvic support—the more likely it will be out of adjustment. Poorly adjusted components can lead to safety problems.

Transportation

The safety of wheelchair users while they are transported is often poorly addressed by clinicians, who should become comfortable distinguishing between wheelchair tie-downs, occupant restraints, and postural-support devices. Wheelchair tie-downs secure the wheelchair to the vehicle. We will not discuss tie-downs in this article except to make one plea: Whenever a new chair is introduced to the market, clinicians should ask how the chair is tied down.

Not all transportation-related injuries are due to a crash—abrupt vehicle maneuvers actually pose the greatest risk to wheelchair users. The latter issue needs to be addressed by using appropriate wheelchair tie-downs. 

Postural Supports

Postural supports must either break free at loads that do not injure a person or be able to withstand the forces that occur during a crash. Currently, the former must be considered, although efforts are under way to design postural supports that also act as occupant restraints. (See www.wheelchairstandards.pitt.edu for an update.) A headrest or trunk-support mount that fractures during a crash, leaving an exposed support rod, is an obvious danger. Less obvious might be a belt that runs over the abdomen and can induce serious internal injuries during a crash. Does this mean that postural supports should be removed during transport? In our opinion, absolutely not.

One postural-support device that breeds much discussion is the lap tray, which is often used to help wheelchair users maintain a functional posture but is clearly an injury risk during abrupt stops or crashes. Some lap trays are meant to mount devices and are not postural supports, so they should be removed during transport. The decision of whether or not to keep them in place during transport is not a simple one. One judicious approach is to remove lap trays during transport, unless the wheelchair user is at high risk of sliding or falling out of the chair during noncrash vehicle maneuvers and no alternatives can be found. This approach considers the use of lap belts and other postural supports in lieu of a lap tray during transportation. These alternative supports might not afford the necessary postural control during functional activities, but they meet the rider’s needs when passively sitting during transport.

Reference

1. Rubin BS, Dube AH, Mitchell EK. Asphyxial deaths due to physical restraint. Arch Fam Med. 1993;2:405–407.