A Question of Weight
In ultralightweight chairs, when does weight matter most?
- By Laurie Watanabe
- Jun 01, 2018
WEIGHT ABSTRACT: ISTOCKPHOTO.COM/NAQIEWEI
In wheelchairs that are self propelled, consumers often fixate on frame weight. In their minds, lighter is obviously better — and there is a general truth to that. Pushing a lighter device is obviously preferable to pushing a heavier one, if all other factors are equal.
But that’s the challenge: So many other factors should be part of the decision-making process when an ultralightweight chair is being selected. There’s never a scenario in which the consumer and the wheeled mobility team are choosing between two chairs identical in every capacity except weight. So when is a chair’s weight truly important?
Transfers & Transport
Josh Anderson, VP at Permobil, has used an ultralightweight chair since his early teens.
“I think consumers fixate on transfer weight because it is something that is so tangible,” he said. “It is harder to quantify some of the other critical elements, like how well a chair rolls (efficiency); how durable is the chair; and is the chair more comfortable and does that make me more functional or able to do more independently?
“These elements are just as important as weight, if not more important than weight.”
Then, when is a chair’s weight important?
Tina Roesler, PT, MS, is International Sales Manager for Motion Composites, said a chair’s transport weight can be a significant consideration.
“When a user or caregiver lifts the chair in and out of a vehicle, they are often at high risk for injury, reaching out for the chair and lifting it,” she noted. “Most of the research says weight does not have a huge impact on propulsion, for example, when the chair is properly configured, but will impact independent transport.”
Anderson said he typically transfers in and out of his car several times a day.
“Transport weight could certainly affect the type of car a person drives or how quickly and easily they get in and out,” he explained. “But the design, the actual dimensions of the frame, has more of an impact on the type of car a person drives and how quickly and easily they are able to get in and out than weight. Weight is not the most important factor for me in transporting my chair. The overall dimensions of the frame are more critical to me being able to independently load my chair in and out of my car.”
Design & Weight
So if we talk about a chair’s weight being most important in terms of lifting the chair into and out of a car — then, is the variable simply a matter of pounds/kilograms? In that case, is the lighter chair the better chair?
Or do other factors — such as one chair’s design vs. a different chair’s design — still play a role?
“Design has an impact, and the package needs to be lightweight and ergonomic,” Roesler said. “However, the biomechanics used by the person lifting the chair is critical. If a user says an ultralight chair is too difficult to transport, we should also be evaluating their method and setup of the transfer into the vehicle. Is the chair too far away from the car? Is the person lifting using proper biomechanics?
“Sometimes we have to re-evaluate functional activities to prevent injury. People easily acquire bad habits!”
“Weight is something that is easily measured from one chair to another,” Anderson said. “Anyone can pick up two chairs and tell which is lighter. Weight is important for transport because typically, when you’re loading your chair in and out of your vehicle, you have to reach for the chair and lift it while it is away from your body, making that weight more significant because it puts additional stress on your body. But weight is not the main factor; design makes a bigger impact than weight for transport.
“Take a traditional rigid box frame design and a modern dualtube or mono-tube frame design. If all three frames are built to the same measurements and weigh the same, the reduced geometry of the mono-tube and dual-tube frames will be much easier to load because that lower frame tube either does not exist or is tucked up close to the upper frame tube, allowing these frame designs to fit through and into a smaller space.”
Folding Frames & Weight
Folding chairs — with their additional components — are typically heavier than rigid counterparts. How does that impact the ease of transporting them?
“Theoretically,” Roesler said, “you do not have to remove any components to load [a folding chair] into the car. However, many may find that the total package is too large, and they have to remove parts anyway. There is also an idea that because they fold, they take up less space. Again, we need to educate and look at every situation. In my small car, for example, a rigid chair actually takes up less space.
“The weight of some chairs, particularly carbon and titanium, has come down significantly… but the ease of transport often comes down to familiarity and the type of car. Again, clients need to be educated about the best and safest way to transport.”
“Folding chairs and rigid chairs break down for transport in completely different ways,” Anderson said. “With a traditional folding chair, you remove the cushion, vertically fold the frame, and remove the rear wheels along with the front footrest hangers for transport. You don’t need to do all of those steps, but you can to reduce overall dimensions of the chair to fit into the smallest possible space.
“With a rigid chair, you remove the cushion, the rear wheels, fold the backrest down and load the chair. Again, you don’t need to do all of those steps, but you can to fit it into the smallest possible space. When I load my rigid chair into my car, all I do is remove the rear wheels, place them behind the passenger seat, and load the frame into the passenger seat. I don’t need to remove the cushion or fold down the backrest, because the overall frame geometry is small enough that I can pass the chair between me and the steering wheel of my car without folding down the backrest. Not having to do extra steps really makes it much easier and faster for anyone to transport their chair.”
Will Design Make the Difference?
Folding chairs are emulating rigid chairs more and more, not just in weight but also in design. Will that evolution ever make a folding chair as easy to transport as a rigid one?
“Design for both rigid and folding chairs has come a long way,” Anderson acknowledged. “Weights can be very similar between a rigid chair and a folding chair. And I’m sure for some people, it is easier to load a folding chair in and out of a vehicle versus a rigid chair. But those users are becoming fewer and fewer. A rigid chair with many vehicles is just a much more compatible package for most users to quickly and easily transport their chair.”
So to circle back to the original question: When should weight be most seriously considered?
“A well-designed and well-configured chair can be easier to propel, but transport is still an issue,” Roesler said. “All recommendations and research show an advantage to lighter chairs, but we have to look carefully. For example, 1 lb. may not make much of a difference, but 3 to 5 lbs. can.”
“I believe,” Anderson said, “that a well-fitted and well-designed chair can be much more efficient to propel than a chair that weighs a few pounds less, but is not well fitted and well designed. Weight does make a difference, and I’m not suggesting that a chair that weighs 50 lbs. is more efficient to propel than a chair that weighs 20 lbs. But two chairs that are within a couple pounds of each other and one having a superior design that fits the individual properly — I believe that will be more efficient to propel.”
Anderson noted his own experiences — as a longtime, active user — as an example of which qualities can be most substantial.
“For me, chair weight is never the most important element. If we are talking about transport, the overall geometry of the frame is more important for being able to get the chair quickly and easily in and out of the vehicle. If we are talking about propulsion, then the design of the frame and the efficiencies gained in transferring my energy into moving forward from that design are more important than the weight of the frame.
“I transfer in and out of my car three to four times per day, but I push 3,000 times per day, and that efficiency of propulsion has a much greater impact on my mobility.”
This article originally appeared in the June 2018 issue of Mobility Management.
Laurie Watanabe is the editor of Mobility Management. She can be reached at email@example.com.