How to Choose Options for an Ultralightweight Chair

• Jul 01, 2010

Of all the consumer groups in the industry, is there a tighter community than ultralightweight chair users? Active, vibrant and expressive, this group is known for customizing their chairs to fit their lifestyles — and for considering their chairs to be extensions of their souls and personalities.

While clinicians and providers tend to focus on frames, seating and backs while matching a consumer to the best ultralight chair, this segment boasts a diverse aftermarket of options. Like seat cushions and backs, these ultralight options can make a big difference in propulsion efficiency, comfort and the overall riding experience.

Wheels

Sure, they can be flashy, but wheels can also have a huge impact on an ultralight’s performance.

For ultralight usage, the goal of a wheel is to be very lightweight to facilitate efficient propulsion by the consumer, while also being very strong. Wheels can also play a role in how much vibration is transmitted from the ground to the consumer, which is important because cumulative vibration or shock can lead to discomfort, increased pain or fatigue for the chair user.

Wheel designs vary greatly and include traditional spoked and composite (molded) designs. Among composite wheels’ claims to fame is ease of maintenance; it generally doesn’t need to be adjusted or trued, as a spoked wheel does. But the same flexibility that can require a spoked wheel to be periodically adjusted can also produce a smoother ride. Spoked wheels have also traditionally weighed less than composite wheels.

Even among spoked wheels, designs vary greatly. Wheels with fewer or strategically placed spokes can make it easier for consumers to reach through to access underneath their chairs, while larger numbers of spokes can provide greater protection for the wheel.

In addition, an aftermarket wheel might actually make the width of the chair narrower, if the aftermarket wheel sits closer to the side of the chair than the original wheel did, and the aftermarket wheel’s hub is similarly narrow.

Tires

Depending on where they go and when, it can make sense for ultralight users to have multiple sets of tires to compensate for different seasons and terrains. Aggressive-tread (knobby) and/or wider tires are specially designed to handle dirt, mud and snow; not so with everyday tires designed mainly for smooth, even surfaces.

Suspension Components

Wheels and tires are a good segue into the world of suspension options. Vibration can impact both the chair and its user, which is why consumers who navigate challenging environments or are susceptible to muscle spasms or pain as a result of vibration may want to improve their chairs’ suspensions, specifically at the front casters.

Improving a chair’s suspension can come at a price, says assistivetech. net, in explaining why many chairs, unlike cars, don’t have suspensions: “This most likely results from the fact that wheelchairs are typically not used to travel over rough terrain, and they rarely experience being dropped. Furthermore, it requires more force to move a manual wheelchair with a suspension/shock absorption system than it does to move a rigid manual wheelchair. This results from the fact that there is more inertia to overcome with the wheelchair that has the suspension system. However, certain mechanical wheelchairs, including those used for sports and for traveling over rough terrain, and most automatic wheelchairs, make use of a suspension system of some type.”

Propulsion Assistance & Pushrims

No matter how lightweight the components, propelling a chair can be tough on its “motor” — in this case, its human user. Despite plenty of studies showing that self-propellers can be prone to shoulder, arm and hand injuries, power-assist systems for manual chairs remain relatively rare. Ditto for systems that enable a user to drive using just one hand/arm instead of two.

More visible on the assistive technology landscape is a two-gear wheel system for manual chairs that reduces the amount of energy needed for propulsion, particularly on inclines.

Also becoming more common are ergonomically designed handrims created to make propulsion more efficient. Such pushrims can be textured to provide greater grip for the hands, or they can be designed to fit the fingers and thumb more precisely and safely, making the handrim easier to grab, hold and push.

Armrests

Many ultralight users forego armrests to reduce weight, make it easier to slide under tables, or maximize range of motion or function. Consumers who do opt for armrests, perhaps to assist with posture, have a wealth of choices, from where and how the armrests are attached to the chair, to whether the armrests are fixed in place or movable to facilitate transfers, to the lengths of the armrests.

Height is also important, as armrests that are too low might cause the user to lean forward to use them. Armrests that are too high could require the user to lift his shoulders to reach them.

Today’s ultralightweight wheelchairs are already highly customizable to meet a range of clinical needs. With the help of assistive technology professionals and all the right options, ultralights can meet their users’ personal and performance needs as well.

This article originally appeared in the July 2010 issue of Mobility Management.