Page 21 - Mobility Management, January 2018

Propulsion as the End Goal
Rather than focusing too intently on an ultralight chair’s weight, the focus should be on propulsion ef ciency, Simoneau said.
“Weight is an important aspect, but the main objective of an ultralight wheel- chair is to achieve a high propulsion ef ciency, which is what changes lives of users,” he noted. “A light wheelchair is
not necessarily ef cient at propulsion, but an ef cient wheelchair won’t be a heavy chair! Ef ciency can be achieved with a combination of characteristics, like weight, well-designed structures and ergonomics to allow the user to travel forward with the least energy possible.”
“From a functional and clinical perspec- tive, the ability to dial in the con guration can be more important than the weight,” Roesler agreed. “While it is nice to have
a lightweight wheelchair, the con gura- tion and the distribution of the weight are more important. For example, weight added to the back of the chair (such
as backpacks) will have more negative impact than weight under the seat when the wheelchair is con gured correctly. So, the adjustability and customization of lightweight chairs is as important, if not more important than weight alone.”
Asked what other characteristics could make or break an ultralightweight chair’s functional success, Ibarra said, “Frame stiffness, which is tied to the ef ciency
of the push, and end-user positioning in the chair, which is going to affect how the chair functions/maneuvers.”
“We strongly feel that t and balance are key considerations because they impact the user in huge ways,” Srinivasan said. “The better the t is for the user, the better balanced they will be in the system. There are many factors that contribute
to good t, but being in control of every aspect of that t is critical to optimizing the functionality.
“Once these concepts are learned, they can be applied to any manual chair frame, including a folding frame that
is less customizable. We are trying to educate the market on a regular basis about these concepts because many
are still misunderstood. The degree to
which you can control, understand and apply these concepts is the key variable. That is why we have chairs that can be adjusted for optimal t or built to an optimal t without adjustments that can both be successful.”
Beauty That’s in the
Eye of the Consumer
While high-grade aluminum, titanium and carbon ber all can offer great strength at low weights, titanium and carbon ber especially are also known for their showy good looks. So how much
adjustability will be an additional factor.” “We do believe that appearance is
highly important, as it appeals to the user, and they use it every day,” Srinivasan said. “But that also doesn’t mean having 52 colors to choose from. We see clients often choose the same groupings of colors and material nishes that go well together. It’s about the package look and how well the system looks as a whole that allows them to feel like they’ve personalized the chair to their style.”
In the end, perhaps an ultralight owner’s overall happiness with his or
MobilityMgmt.com
MOBILITY MANAGEMENT | JANUARY 2018 21
Considering that the frame weight is only 20 to 25 percent of the average total weight of the chair, the type of material you choose is just ounces of a difference —Jesus Ibarra
attention do manufacturers pay
to the appearance of their ultralight- weight wheelchairs?
And are there other characteristics or traits that should be considered just as critical to ultralight success?
“Weight and appearance are indeed two important factors,” Simoneau said. “A light wheelchair will generally offer more performance, and a well-designed product will be visually more attractive. Other very important factors are propulsion ef ciency, comfort and durability. Lightness should not be a compromise with quality of wheelchair components, but being a result of innovation and optimization of overall assembly!”
Ibarra said he agrees that weight and appearance are important to consumers, and thereby worthy of manufacturer attention. “But it also comes down to the type of user that’s acquiring the chair,”
he noted. “If you have a very active user (two to four years after injury) that is completely dialed in on his needs (chair con guration), then weight and aesthetics will be their main concerns.
“But for a [newly injured client], where he still needs to review between going to a rigid frame or a folding frame, [wheelchair]
her wheelchair is less about weight or
a certain frame material than about functional success — the chair’s ability to perform well because it ts its user properly and is ideally equipped with the right components and accessories.
“It is important that the client is the center point when they enter a room,
and not the equipment,” Srinivasan said. “You see the same things in high-end auto manufacturers: They spend a lot of effort putting packages together that all blend nicely. They sort of do the work
for the consumer while still offering a personal touch. So, while weight and a chair’s appearance should get attention, the focus should be on how to achieve the best possible t and function, allowing users to prevent upper-extremity injuries to shoulders, wrists and elbows over time while using the chair.”
“In the end, the consumer’s opinion is the most important,” Roesler said. “Clinicians need to work with the client to be sure all the needs are met, including appearance! If someone feels good and looks good in their wheelchair, they are more likely to use the chair and function at a higher level. We really need to relate everything back to client- centered prescription.” m