As an editor, I’m supposed to be fascinated by every complex rehab technology (CRT) segment. For the most part, I am. But I have favorites. And seating has always been one of them.

While power wheelchair bases with sophisticated suspensions and minimalist ultralightweight frames made of aerospace materials are fun and flashy, their seating is the foundation upon which function is built. The right seating can provide stability, optimal weight distribution, and the positioning required to safely perform activities of daily living.

While seating might appear to be a straightforward process of designing and developing products such as seat cushions, then manufacturing them and bringing them to market, there’s also a lot of activity taking place in meeting rooms and on conference calls such as those held by the RESNA Standards Committee on Wheelchair and Related Seating (WRS), chaired by Kara Kopplin, Director of Regulatory Science at Permobil Seating & Positioning.

Wide-Ranging Seating Goals

The most recent (at press time) meeting of the WRS committee was via conference call in October 2019. Committee members vary in their day jobs; some, such as Kopplin, Susan Cwiertnia (VARILITE), and Matthew Kosh (Bodypoint), are affiliated with seating manufacturers. Others, such as Dave Brienza, Barbara Crane, and Sharon Sonenblum, have university affiliations. But they all have a deep interest in seating and the desire to make tomorrow’s interventions even better than today’s.

On that October conference call, the seating topics included a discussion on cushion material flammability, with a cigarette being used as the heating source. To strive for consistency in any future flammability testing involving cigarettes, the committee talked about building a pendulum-like device to hold the cigarette in constant contact with the cushion… and about how to create a pendulum device simple enough to be cost effectively replicated by other testing sources.

The committee talked about the impact of microclimate on cushion function, and about immersion tests using indenters — basically, mechanical “butt models.” But the portion of the conversation that most interested me was cushion aging.

We know why complex rehab cushions age. Wheelchair users transfer on and off of them multiple times a day. Cushions are exposed to heat and cold, and moisture from precipitation, food spills, and incontinence. But how long can a cushion do its job before it starts failing? How should cushion failure be defined by the industry? And how long does it take a cushion to wear out?

“An Exciting Time”

That last question is one that has profound implications for wheelchair users. When a wheelchair cushion wears out before its “reasonable useful lifetime” has elapsed, the consumer’s funding source will typically decline to pay for a new one. That leaves the consumer with two choices: to buy a replacement out of pocket, or, if that’s not possible, to keep using a less-than-optimal cushion.

So far, cushions subjected to simulated aging have tested very differently afterward. Understanding the wide range of test scores is one of the committee’s ongoing challenges.

“It is an exciting time to be a part of the RESNA WRS committee, as members from clinics, universities, industry, test labs, and public policy are all working to shape the future of wheelchair seating and positioning,” Kopplin told Mobility Management. “The work is not only around testing, but also developing common language for better understanding and unification. These standards provide a foundation for innovation, and help ensure safe and effective products are available.

“Participants who work in funding and reimbursement are also strong participants, poised to potentially adopt and promote new standards in the future. Our group is very welcoming and collaborative, with the standards being developed ‘by us and for us,’ as member Kelly Waugh pointed out. We would love to have new participants lend their perspectives!”

Listening to these seating experts share, question and brainstorm was a treat, an enlightening experience for those who love thinking about seating’s possibilities. The committee welcomes anyone who’s interested in joining or listening in; for more information, check out the RESNA Web site: https://tinyurl.com/resnawrs.