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Somewhere to Go

How Dynamic Seating Can Help Manage Otherwise Harmful Forces

• By Laurie Watanabe
• Oct 01, 2022

Dynamic wheelchair seating can be helpful for many clients, from those who exhibit seemingly superhuman strength and tone when in static seating, to those who benefit from moving while sitting, to those who need assistance to stay properly positioned.

While wheelchair seating that moves might seem a bit counter-intuitive — Aren’t wheelchairs supposed to provide stability? — Jessica Presperin Pedersen, OTD, MBA, OTR/L, ATP/SMS, FAOTA, the Director of Clinical Education for Sunrise North America, pointed out that the ability to move while in a wheelchair does mimic how able-bodied people move.

“We constantly move,” she said. “We’re moving now. It’s not like we’re static. And so for somebody who doesn’t have that ability, can we incorporate that ability?”

Michelle L. Lange, OTR/L, ABDA, ATP/SMS, Access to Independence Inc., sees the benefits of being able to move while seated in a wheelchair. “I’d love to see movement be built [into wheelchair seating] a lot more,” she said. “There are people who use wheelchairs that can move within their wheelchair fine. Maybe I’m a [paraplegic], and I’m propelling my manual chair, and I can move around. Even if I don’t always have sensation, I can choose to move. So I might [lean to one side] for a while because I feel like it, and I can do that and get myself back into position. But there are a lot of clients who can’t move themselves within their wheelchair seating system.”

That’s when dynamic seating can be helpful. “Dynamic seating is movement that occurs within the seat and/or wheelchair frame in response to client movement and force,” Lange said. “Dynamic components absorb force which, in turn, assists the client back to a starting position.”

Preventing Potential Injury & Equipment Breakage

Dynamic seating components can be helpful to different wheelchair clients for different reasons.

Pedersen cited the RESNA Position on the Application of Dynamic Seating, a paper available at resna.org. She and Lange were among the paper’s authors.

“To paraphrase: Two big things that we look at is we want to protect that individual so that they don’t hurt themselves,” Pedersen said about the position paper. “If they’re having hyper-extension in their trunk or in their legs, they’ll come back [into position]. And they won’t get hurt.

“And the equipment won’t get broken. So it’s a two-way situation. You’re trying not to have this continued breakage, because you have somebody with such powerful force that they break the footrest or they crack the backrest. You can have that dynamic component that will afford them that resistance and then save the equipment.”

Lange said it’s important that this force exerted by clients be given a safe outlet, a harmless way to be expended. Otherwise, the force is turned back onto the client.

“It’s going into the joints,” Lange said. “What happens is clients move out of position — like standing up in their seating system during extension — and then they don’t land back in an appropriate position, often winding up in a posterior pelvic tilt. And also, that unrelieved force goes somewhere, and it’s usually their joints.”

She recalled a report she read: “There was an interesting article about adults with cerebral palsy who developed arthritis in their joints far earlier than the average population. I think a lot of it is because you have these massive forces, and if you can’t move to relieve those forces, they’re going to end up where there’s any movement — and that’s in the joints. There’s a little movement in the joints, and you’ve got this huge force. Can you imagine what your knees would feel like if you were exerting enough force for your legs to stand up in your chair, to move your footrest out of position and sometimes to even break the footrest hanger?”

“You don’t want that femur jamming into the acetabular joint,” Pedersen affirmed. “You don’t want something happening with the ankles or the knees. And so you’ve got to look at those three joints and see where you want that dynamic to come into play.”

Providing Crucial Sensory Input

For other consumers, dynamic seating provides helpful sensory input. While parents and teachers have long admonished children to “Sit still and pay attention,” today’s classrooms are more likely to embrace movement while learning.

“If you look at school districts that have an understanding of that need for movement, you’ll see that children will have fidget [toys], they’ll be sitting on cushions that allow movement, they’ll be allowed to stand up if they can stand up,” Pedersen said. “They’re allowed to do that. A lot of school chairs have tennis balls on their feet that allow a child to slide back and forth. There are rubber bands put underneath the children’s feet so they can push on those.

“I think that the occupational therapists that have incorporated that into the school systems have seen success, and the teachers have been thankful that they found something for their students. So now let’s incorporate that for children that aren’t in regular school desks and don’t have the ability to stand up and move. Let’s incorporate that into their wheelchairs. I think that’s where we’re coming into play, to say that we want to allow that type of movement as well.”

That ability to move is crucial for some wheelchair clients to optimally function.

“There are people who seek out movement,” Lange said. “There’s a group of people that could represent a lot of different diagnoses who just need to rock. And if they rock, they’re more alert and engaged. If you block that need, you get someone who either gets very agitated or perhaps shuts down.”

She described a client “who was spending most of her day at school [with her head down]. And she just looked like she was asleep all the time. But Mom said at home, she sat in a standard rocking chair, and she would just rock all day long and her head would be up and her eyes would be open. But at school she couldn’t rock. So she just looked like she was asleep. She wasn’t. She was just really withdrawn, really shut down.”

Lange and the seating team added dynamic seating to the girl’s wheelchair. “We had to move it for her to show her, because she had been in a static wheelchair for so long. And she finally started moving a little and realized, ‘Hey, I can move.’ She still had some times, probably when she was not happy with whatever they were doing in the classroom, that she would [keep her head down]. But she was spending much more time alert and using her communication device and participating because she could move. She needed that sensory simulation so much.”

If dynamic seating isn’t provided, Lange added, clients will try hard to move on their own. “We have a case study on the Seating Dynamics site of Phillip. Philip had a non-dynamic seating system, but he rocked so much of the time that his back looked like a dynamic back, because it was so worn out. I was just hoping we could get him something before his back exploded because I was afraid he’d hurt himself. That’s a real risk, too, because if I’m moving and my back cane goes snap, what do you think could happen?

“He had worn all those round holes in the frame into big ovals. And when I looked on the back of his chair, there was this fine silver powder. It was aluminum dust from all the force damaging the frame. So the back was moving. But first of all, it wasn’t helping him come back because there was no dynamic component. He was destroying the chair. There were big chunks missing out of his solid tires. I asked the therapist why, and they said they’d put on the wheel locks because he’d rock so hard that the chair would move across the room. He had so much force that, as he was rocking, he would break the tire off under the wheel lock repeatedly, and then they’d move the tire and lock it again.”

Provided with a dynamic seating system for his new chair, Philip was much happier, Lange said. “He can rock, and he loves it. No more chunks out of the tires, no more bouncing across the room with his chair, and he’s not agitated. He’s very happy that he can move. And some of the staff at his residential facility were saying, ‘Is it okay to let him rock all day?’ Because you can lock out the back on most of these [systems].

“Sure, there’s not a problem with rocking. If he rocks, it’s because he’s feeling that need to rock at that time. And if he stops, that’s fine. The back will just stop moving because he has. You don’t have to run over and lock it. When he decides ‘I need to rock again,’ it’s ready to go.”

Matching Dynamic Options to Varying Needs

The types of dynamic components needed varies from client to client.

“Some individuals, probably [people who rock], need back and knee [movement],” Pedersen said. “Or I’ll have somebody that’s extending their foot a lot; then I’m focusing on dynamic movement at the footplate.

“With [clients who rock], a lot of times it’s just [affecting] the back. [For someone who bangs their head], I might need to really provide a lot of stability so they can move their head back and forth, and everything else is stable, and they’re not sliding out of the chair. But I can’t stabilize their head. That [head positioning support] has to give, or they’re going to hurt themselves or they’re going to break the chair.”

Pedersen also has worked with people who have weak back musculature or a spinal cord injury. “So here, you are working to increase a person’s function,” she said. “You’re not fighting tone; it’s not a sensory issue. You’re really saying, ‘Do you need help being able to rotate and pick something up over here and then come back into position?’”

One example of a backrest line with that sort of dynamic movement is Tarta, distributed by Stealth Products in the United States. Typically placed just above the pelvis or a little higher than that, this kind of back allows movement so the wheelchair rider can reach back, for example. But then it guides the rider back into place. Tarta backs can also allow rotation from the rider.

“It’s a weakness issue,” Pedersen said of wheelchair users who would benefit from that kind of dynamic movement. “You are accommodating and giving them that range that they don’t have. They can extend, but they can’t extend that much. So now they’re extending, and they can say, ‘Wow, I can reach this ball back here and now I can throw it forward, and the back’s going to come back with me so that I’m not stuck back there.” It’s the same thing with reaching: If I wanted to reach across, [a dynamic] back will allow me to reach and then bring me back. Now I can come back across midline.”

The uniqueness of clients who could benefit from dynamic seating is part of the challenge, Lange said. For instance, for clients with extension or high tone, “You never know when they’re going to initiate, how far, how long, and with how much force. It can be different each time. That’s a trick with dynamic seating, too: You have to capture force that can be intermittent. It can sometimes last for a while. It could be more force this time and less force next time. I might have a little rotation next time. So there’s a different pattern each time. And that’s really a challenge design-wise for the dynamic component to respond to these varying degrees, travel, and patterns of movement.”

The Future of Dynamic Seating

The funding aspect of dynamic seating is still evolving, with its reimbursement still under debate, at least from a Centers for Medicare & Medicaid Services perspective (see sidebar).

But from a technology standpoint, what might the next generation of dynamic seating be like?

Pedersen referenced, for example, backrests that would work with their users’ own motions. “That to me is the future of dynamic seating: To try to incorporate a person’s real movement. If they can’t get through that full range, can we have the dynamic components that are lightweight and of course inexpensive that would go on the chair that would allow that movement and [allow the wheelchair rider to] come back? Then you’d see a lot more support and probably a lot less back pain, a lot less fatigue, a lot less strain and repetitive injuries because you have something that’s dynamically working with them so that they’re not doing all the work.”

Think of more ergonomic and robust office chairs, with backrests that allow users to lean back to a certain degree, then, when that force is relaxed, bring the users to their original, more upright position.

“So with office chairs, there are some that have rotation,” Pedersen said. “You can go back on that office chair, you have that nice stretch, and then it’ll bring you back. You’re not hanging off the chair.

“I see the future of dynamic systems is lighter weight, but with the same strength for all those forces that you need for your [clients who rock]. And then for the more active individuals that just need that little bit [of movement and support] to be incorporated into their seating system.”

Lange is hoping for future systems with greater transportability. “Our industry needs a dynamic back that readily folds down to ease transport,” she said.

(Currently, Sunrise Medical’s backs for its manual tilt-in-space Quickie and Zippie IRIS wheelchairs do fold.)

“Not all of the dynamic head support hardware ‘locks out,’ and this can be helpful when going over rough terrain or during feeding,” she added.

And perhaps along with improving technology, more education on dynamic seating could also be helpful so healthcare professionals have a better understanding of who could benefit… and when.

Lange remembered a therapist who knew a client who routinely broke headrests. The seating team responded by adding more robust headrest hardware. As it could no longer be dispersed through the headrest, the tremendous force was reabsorbed by the client, who fractured two neck vertebrae as a result.

“This is not a time where you want something tougher,” Lange explained. “You want to let [the headrest] move, because tougher didn’t absorb the force. The force went somewhere, and the client fractured two vertebrae.”

She also recalled a different client who suffered from chronic pain and injuries while in a static seating system. “Before we got him a dynamic footrest, he fractured his femur and dislocated both his patellae. And it was from pushing, pushing, pushing. His knees were red and swollen all the time.

“We got him dynamic footrests and his parents said, ‘We will never, ever, ever go back to a static chair.’ Because they said his knees aren’t swollen and red anymore. And he can sit in the chair all day.”

This article originally appeared in the issue of .