Imagine sitting in a wheelchair clinic with a new client in need of a first wheelchair. You have 1 hour to complete a standard evaluation, take a snapshot of activities of daily living, understand the client’s environment, and listen to concerns about using a wheelchair. The end goal is to determine the one product solution that will serve as an extension of the client’s body for the next 5 years. You may feel pressure at the enormity of this task, asking yourself, “Where to begin?”
There are many considerations when prescribing an ultra lightweight wheelchair, whether it is for a client who is pediatric, an adult, or an older adult. By gaining an appreciation of an ultra lightweight wheelchair’s differentiating features and understanding how those features can affect a client’s needs, clinicians can learn to narrow options for the product that will help achieve the best possible outcomes.
An ultra lightweight wheelchair is best defined as an optimally custom-configured wheelchair that provides independent propulsion that otherwise cannot be achieved by use of a standard lightweight or high strength lightweight wheelchair. Ideally, the ultra lightweight wheelchair has an adjustable rear axle plate, weighs less than 30 pounds, and carries a minimum 5-year warranty on the frame and cross brace, if applicable.
CHOOSING BETWEEN A RIGID FRAME AND FOLDING FRAME
After completing a thorough assessment, determine whether the client should receive a rigid frame or folding frame. Rigid frames tend to offer the most efficient propulsion when set up properly. They also involve fewer moving parts (such as cross braces, swing-away legrests, etc) that absorb energy generated from a push on the rear wheels. In addition to increased performance, there is an overall weight decrease as a result of fewer moving parts. Most rigid frames utilize a cantilever design that allows for a smaller footprint, eliminates lower side frames such as those seen on folding chairs, and can make it easier for the user to transport the chair. Rigid frames also often offer greater opportunities to achieve a custom fit.
With many favorable features associated with rigid wheelchair technology, one may wonder why a clinician would prescribe a folding chair. To begin with, several folding chairs offer both width and depth growth capabilities. Depending on transfer status, swing-away legrests may allow for easier squat and stand pivot transfers. They also tend to accommodate a wider range of knee angles for proper weight bearing on the foot plates. While rigid frames typically offer only 75°, 80°, and 85° front frame angles, folding chairs offer 60°, 70°, 80°, 90°, elevating, and articulating legrests. Finally, depending on transportation needs, a chair that collapses in half and fits in a trunk of a vehicle without removing the wheels certainly has its appeal. The client and/or caregiver should have the opportunity to lift both a rigid frame (after removing the wheels) and a folding wheelchair into a vehicle to determine which option is most efficient.
UNDERSTANDING LISTED PRODUCT WEIGHTS
A year ago, I received a call from a therapist asking why one folding wheelchair weighed 15 pounds more than another folding wheelchair in the same category. I explained that the potential cause of the weight differences may be the difference in published weights. In this case, the transport weight was listed on the lighter wheelchair, rather than the overall weight. Transport weight is defined as the weight of the frame, seat and backrest upholstery, front casters, caster assembly, and wheel locks, or the weight of the wheelchair excluding all parts that are removable without tools. While this measurement may be beneficial for an individual lifting a frame in and out of a vehicle, it can be very misleading when trying to determine the weight a client will have to propel. Typically, a fully configured, 16-inch-wide by 16-inch-deep, folding ultra lightweight wheelchair (including 24-inch rear wheels, antitips, legrests, armrests, wheel locks, push handles, and seat and back upholstery) will weigh in the upper 20-pound range.
Removing only 3 pounds from the weight of a wheelchair could mean that an active user who completes an average of 2,000 push cycles per day could save the upper extremities from pushing an additional 2.2 million pounds per year.
COMPARING WHEELCHAIR WEIGHT AND SETUP
Is the lightest wheelchair always the best option for a client? It depends. I learned some time ago that shaving a mere 3 pounds off the weight of a wheelchair could mean that an active user who completes an average of 2,000 push cycles per day could save the upper extremities from pushing an additional 2.2 million pounds per year. As significant as this statistic sounds, most suppliers and manufacturers agree weight is only half of the equation. The other half is the configuration, or setup. A friend of mine had me test two ultra lightweight, aluminum wheelchairs while blindfolded. One wheelchair weighed 6 pounds more than the other, but its configuration provided better access to the rear wheels. For this reason, the heavier wheelchair was easier to propel. Ultra lightweight wheelchairs are also built to provide an adjustable axle plate, which allows for center-of-gravity, camber, spacing to and from the side frame, and seat-to-floor height adjustments. The proper wheel position also can make a world of difference to clients’ upper extremities. A general rule of thumb states that if users hang their arms to the side while seated in the wheelchair, the axle should be positioned at the tip of the middle finger. If you do not feel comfortable making the adjustment, reach out to your vendor or manufacturer’s representative, who may be a valuable resource in this area.
BALANCING MATERIAL AND DESIGN
With an astounding rate of advances in aluminum frame technology, coupled with the option of titanium frames, the modern ultra lightweight wheelchair is designed to utilize as few steel components as possible, resulting in a tremendous weight savings and excellent durability. Titanium frames are lighter than T6061 aluminum frames, but can also be more costly. A frame recently has been introduced that is manufactured from heat-treated 7000 series aluminum combined with an advanced redesign of the rigid frame that features oval tubing and an optimized caster position. The combination of material and design is engineered to create a frame that is lighter than titanium or standard aluminum, possesses equal strength, and offers efficient propulsion.
RECOGNIZING THE EFFECT OF OPTIONS AND ACCESSORIES
Have you ever prescribed what you thought would be a 17-pound rigid wheelchair, only to realize the final product was 10 pounds heavier than expected? A common culprit of weight increase is rear tires with solid, airless inserts. Although highly valued for their minimal maintenance, a pair of these tires can add 2 pounds to an ultra lightweight wheelchair. A pair of single-post armrests with desk length pads can add another 5.5 pounds. While certain options may be necessary or desired, you may have to make compromises when determining whether the option or the weight is most important. Some order forms include helpful matrices that allow the overall weight of a specific configuration to be calculated. Research these options to set a realistic expectation for the client.
One of the most important frame features for pediatric clients is growth. Most wheelchairs offer a one-time replacement frame to accommodate growth.
SPECIAL CONSIDERATIONS FOR PEDIATRIC CLIENTS
Today, most manufacturers have designed rigid frame wheelchairs specifically for children. These wheelchairs feature reduced weights available in sizes as small as 8-inch wide by 8-inch deep. One of the most important frame features for pediatric clients is growth. Most pediatric wheelchairs offer a growth kit or a one-time replacement frame to accommodate width growth, while some amount of depth growth is often built in. The options and accessories dilemma addressed earlier is even more critical to consider when working with children. For example, a 175-pound adult in a 27-pound wheelchair is propelling only 15% of body weight, while a 38-pound child in that same wheelchair is propelling 70% of body weight.
Another consideration for pediatric wheelchair users is transit. Talk to manufacturer representatives to better understand whether the product has a transit or tie-down option. As you would with an adult, assess transfer styles and environmental demands for the client and caregivers before prescribing an ultra lightweight wheelchair.
SPECIAL CONSIDERATIONS FOR ACTIVE ADULT CLIENTS
Active adults represent the greatest population of ultra lightweight wheelchair users. Key characteristics they seek include performance, lightweight frames and options, durability, transportability, adjustability, and sleek design. Environmental concerns may include vehicle and transportation considerations, community accessibility, workplace access, and the ability to perform Mobility Related Activities of Daily Living (MRADLs). It is prudent to keep in mind these individuals have the highest incidence of upper extremity pain and are highly susceptible to carpal tunnel syndrome and repetitive strain injuries at the shoulder, elbow, and wrist. Prescribing the correct frame, whether folding or rigid, and properly fitting the frame for clients can help decrease the rate of occurrence.
SPECIAL CONSIDERATIONS FOR AGING CLIENTS
As we age, joints and muscles glide and stretch less. This effect certainly has an impact on wheelchair propulsion. With an adjustable axle plate, the rear wheels may be set up in the most supportive position to increase propulsion efficiency. Ultra lightweight wheelchairs offer increased seat-to-floor height ranges as well. Configuring a wheelchair with a superlow seat-to-floor height is an important option for a client who may need to foot propel. Many of our geriatric clients have a calendar filled with appointments to various facilities, making the option of transit tie-downs critical. Another important consideration for older adult patients is that some areas of the country will allow wheelchair users to utilize public transportation only if there is a transit system on the wheelchair.
Multiple manufacturers design innovative products within the ultra lightweight wheelchair category. The sheer number of frame options can be intimidating. By applying clinical assessment findings and an understanding of these key considerations, clinicians will be able to maximize the benefits of an ultra lightweight wheelchair and achieve the best possible outcome for the people they serve.
Steve Boucher, OTR/L, Clinical Education Specialist, Sunrise Medical, earned a Bachelor of Science in Occupational Therapy from the University of New England. He practiced as a Level II inpatient clinician at Fairlawn Rehabilitation Hospital and served as a Rehab Manager at Northeast Specialty Hospital. Boucher resides in Worcester, Mass. For more information contact .