ATP Series

All About Asymmetries

Each Asymmetrical Posture Is Unique... And Sometimes Surprisingly Functional

• By Laurie Watanabe
• Oct 01, 2022

Does asymmetry get a bad rap? If a person’s posture isn’t identical — left side vs. right — is that always detrimental? Or are asymmetrical postures sometimes misunderstood?

Daniela Giles, PT, DPT, ATP/SMS, is Clinical Educator at Ride Designs. “Asymmetry in itself is not pathological,” she said. “Asymmetry is required. Able-bodied people use asymmetry all the time. We use it for stability. We use it to relax and stay in a certain position. If we all sit in perfect symmetry, one — we usually can’t rest. And two, we usually can’t do anything effectively.”

Think about your last Zoom call and the number of times you crossed and uncrossed your legs as the minutes ticked by.

“We need [asymmetrical postures] for passive stability, and then we need it actively for power and control,” Giles said. “We use the example of a pitcher, or a soccer [player] getting ready to kick. They’re going to wind up into the most asymmetry possible to create power when they release through those ranges.”

In that same way, a wheelchair rider might find an asymmetrical posture to be functional. “Sometimes, the asymmetry is very helpful,” Giles said. “They like it, and they don’t want to change.”

Asymmetries & the Seating Assessment

Of course, just because an asymmetrical posture is helpful doesn’t necessarily mean it’s sustainable. Therefore, Giles said that carefully observing what the client does and says during the seating assessment is crucial.

“Any good assessment starts with listening,” she explained. “It’s a listening, listening, listening, patient-centered model. We’re not just looking at asymmetry and making a change arbitrarily. [Changes] are related to what they say, and what they need, and what their environment entails.

“We have to listen to the body as well. When I’m observing, I’m listening to their body and their movements. Listening would also include getting the detailed medical history. Whether you’re reading that history or it’s been given to you, you really have to try to gather that big picture, and that comes through listening. We always have to start with that.”

Tina Roesler, PT, MS, ABDA, Director of Clinical and Business Development at Bodypoint, agreed that getting a comprehensive medical history is important.

“I wouldn’t address an assessment with someone with asymmetrical posture any differently at the beginning,” she said. “I might dive more into the anatomical reasons why there’s an asymmetrical posture, how long it’s been there, if it’s reducible or not reducible, all of those kinds of things. But that would be something that almost any wheelchair evaluation should follow and go into.

“I think it ties back into their goals, and it’s going to be different for each person. How reducible is it, and how much do they tolerate a new change in position, for example? And then what I look at, especially when you start talking about applying secondary postural supports, is — when I support them in what maybe is the ideal position, what happens to their function? Because sometimes they’re used to a position and they’re functioning in that position. If I change it too much, maybe now they lose function, which is the last thing we want to see.”

As for when asymmetrical postures become problematic, Giles said, “Where it becomes pathological for our wheelchair users is when it’s always one way. Able-bodied people will lean one way, and then lean the other way. We get uncomfortable in one position], so we go to another position. We might lean forward or we might lean back.

“But in the wheelchair user population a lot of times, why they [demonstrate] a certain level of asymmetry is disability related. They had surgery, they had a hemipelvectomy, they had a [surgical] fusion. That creates the propensity towards an asymmetry in one specific direction.”

And since that asymmetry takes place in the same specific direction, Giles added, that asymmetrical position becomes the new norm. “When it’s consistent and persistent in a single direction, the tissues will accommodate to that,” she said. “The joint capsule gets tight. Range of motion, muscles, ligaments — everything changes, and they lose the ability to go through midline to the other side. This is pathological. This is asymmetry that is not okay and that we need to look at.”

Understanding Fixed vs. Flexible

When discussion turns to whether an asymmetrical posture should be accommodated or corrected, Giles said it’s important to understand what a “fixed” posture truly is.

Ride Designs’ philosophy, she explained, is that joints or body segments shouldn’t be considered fixed “unless they do not move at all. In the description that we were talking about — consistent and persistent one way versus the other way — oftentimes, we will look at a joint, and we will say, ‘Does it correct?’ If someone’s got a left pelvic obliquity, can we correct it towards neutral or through neutral?

“If it doesn’t correct or it’s really stiff, we might say, ‘That’s a fixed pelvic obliquity.’ But that’s erroneous, because most of the time, there’s flexibility for that to progress into a worsening level of obliquity in that direction.”

So if a lack of intervention is likely to result in the asymmetry continuing to progress, then change is still possible.

“Yes, and change for the worst,” Giles said. “This is why we see, when that person comes [to clinic] a year later — no, they don’t have a right obliquity, but they have a worsened left obliquity. We say it’s not fixed unless it’s pathologically or surgically fused. If a surgeon fuses that joint and puts in pins and a rod, that is fused.

“We know that even rods can change and shift, so even those joints can still progress. And there are pathological fusions, like a severe [rheumatoid arthritis] or heterotopic ossification, where the bone kind of fuses. That joint is not going anywhere. It’s not likely to get worse, it’s not likely to get better.”

The terminology is important, Giles believes, to understanding how actions or inactions could impact the wheelchair rider’s future positioning. “When we talk about fixed versus flexible, we have to be accurate in our terms, because most of the time, those joints can get worse, and we want to prevent that.”

Seating Goals for Asymmetrical Postures

Giles keeps three goals in mind during the seating assessment. “The three main goals of most of our seating systems are preserving or improving alignment,” she noted. “So — an alignment goal, a functional goal, and then you’re trying to meet those two while maintaining skin safety.

“We have to try to maximize function and maximize proper alignment, while not sacrificing any level of skin care. And again, that skin care is very specific [to the client]. Are they pediatric, are they geriatric? What you’ll be able to do in alignment versus skin is specific to each case.”

Plus, Giles noted, most wheelchair riders come to clinic because something specific is bothering them. “There’s usually one reason they came in,” Giles said. “‘I have a sore’ or ‘I can’t transfer,’ or ‘My body hurts now that it’s in this alignment.’ There’s always a primary goal of why they’re coming in. I will prioritize those three items by level of importance to them.”

Giles said fine-tuning those three goals — dialing one up a bit while dialing another down — is necessary to making sure all needs are being met as well as possible. “If they have a wound and the skin is of the utmost importance, I might [move] alignment and posture down on the list for a while. Let’s allow you to sit, let’s preserve your skin and allow you to transfer. I will sacrifice my alignment goals for the preservation of skin. So those three things can be kind of jumbled.

“If you’ve got a kid with very low skin risk, that’s third on the list, because we don’t really have a lot of risk or concerns there. I can go bigger and put the functional [goals] and the alignment a little bit higher on my goal list.”

The Role of Secondary Postural Supports

While wheelchair backs and seat cushions are a big part of the positioning process, Roesler pointed out that secondary postural supports are crucial to dialing in precise positioning — a requirement that can be extra important for the client presenting with an asymmetrical posture.

“They encourage you back to your original position,” Roesler said in explaining the role of supports such as harnesses and belts. “It’s important to remember that while a lot of people think of chest harnesses and pelvic belts as restraints, that’s completely the opposite of what Bodypoint believes [see sidebar]. It’s not a restraint. It should facilitate better function and keep that person stable. And in some cases, the supports just help [wheelchair users] to be stable when going over bumps in a power chair.”

While it’s easy to find cheap wheelchair restraints online, Roesler explained that secondary supports for clients with complex positioning needs are much more robust in function.

“The [Bodypoint] PivotFit harness has stretch or non-stretch [versions], depending on how strong you want that positioning to be at the chest and the upper extremities,” she said. “Also, it uses our Swivel Buckle, a round buckle that fits into a little circular receiver. It swivels just enough so if that person needs to function and move, the buckle moves with them and allows for some of that trunk motion without impeding them.”

That’s important because wheelchair riders move in multiple directions and rotate as they do. “We’re not only talking about moving very neatly in a single direction,” Roesler said. “There’s rotation as well. We will turn and reach for something on the left or the right. I especially like that buckle, because it really allows you a little bit more motion all the way through the harness.”

Complex seating supports are available in different versions that allow more or less movement while still promoting function. “Maybe someone needs a chest harness with firmer control,” Roesler said. “Maybe the harness is not flexible; maybe that’s what allows them to use their upper extremity to reach a joystick, for example, because they’re maintaining that upper-body stability. And the same thing with a pelvic positioning belt — if I talk about harnesses, I always assume that they’ll also have a pelvic positioning belt. Because if my pelvis is moving around under the harness, it creates other issues.”

Roesler added that secondary postural supports should be part of the seating system’s configuration from the very beginning. “You can’t talk about cushions and backs unless you have a good base of support,” Roesler said by way of comparison. “You can’t just say, ‘We’re going to use this cushion, this back, these postural supports, so let’s just pick any chair,’ because it won’t work. They all interface together. So you have to consider the interface with all of those components together.”

Today’s postural supports can be precisely placed thanks to greater numbers of positioning options. Those options are partly needed, Roesler said, because supports must be compatible with such a large number of wheelchairs. “But also, we have so many different types [of supports] not just for the interface with the wheelchair, but also exactly where that strap needs to go.”

In the past, limited mounting options sometimes forced clinicians to compromise, Roesler added. “When I was out in the field years ago, I knew [a therapist] who always put a backrest up 2" higher because it allowed the straps on the harness to be in the right place. But then inadvertently, if the person had upper-extremity motion, their motion was blocked because the backrest was so high. But [the therapist thought] it was more important that the harness be in the right position.

“With things like [Bodypoint’s] Strap Guides, you could have an appropriately positioned, super-low back, but still have a harness in the right position, and their upper extremities would still be free to move throughout the range of motion.”

Roesler also explained the fine-tuning ability of today’s postural supports: “Most of our harnesses are called multi-directional harnesses. So I can choose whether I want the pull to be forward or rearward. In some cases, if someone’s really asymmetrical, maybe I want one rear so I can pull harder posteriorly and one forward just to do adjustments. So you have that versatility with a lot of our harnesses as well.

“And the same thing when you’re choosing the pull for a pelvic belt: Do I want it to be a rear pull, front pull, or a center pull? Center pull is obviously most standard. It’s one pull, one direction. But if I have someone who’s really asymmetrical and I really want to control the pelvis, maybe I need something that I can pull backwards. We actually call it a front pull, or pull forward to correct that pelvic obliquity.”

Secondary postural supports give seating teams another layer of positioning intervention. “You want the right kind of control with the secondary postural supports,” Roesler said. “And again, without [the supports] being restraints. You’re not trying to tie someone in the chair. You’re trying to still facilitate what function they might have, and hopefully help reduce or slow down the progression of an asymmetrical posture. We know that it’s not usually possible to completely eliminate that asymmetrical posture or stop it without surgery or things like that, but we do want to try to control it or slow it down if we can.”

The Tasks Riders Perform in Their Wheelchairs

When creating the optimal seating system, Giles said her strategy is to list what the client needs to do in the wheelchair — “They push, transfer, rest, sleep, cath” — and then classify those activities as rest, fine motor, or gross motor.

“Rest is always the number-one goal,” she noted. “We are looking for a position where they can release their muscles and still stay in alignment. Can I provide support systems and support surfaces to allow them to rest and not go intoasymmetry? Or as minimal an asymmetry as possible?”

Next, “We try to maintain that alignment for fine-motor tasks,” Giles said. “Fine-motor tasks are ‘close to home’ — hair, makeup, two-handed activities that are close to your body. We want to see them supported to where they can use both hands, and not have to shift and find a spot to sit [to be able to] pick up their elbow.

“And then, number three is everything else: Gross motor. What is the proper alignment for gross motor?”

At that point in her educational presentation, Giles said she pauses and waits for someone to say, “Well, what is the task? What is the thing that they have to do?”

“Because the position, the proper alignment, the best alignment is the alignment that gets the job done, and it may be drastically different” according to the task, she explained. “The example I use is it’s different to push uphill than to push downhill. Your body will be in a different alignment. And so, what we try to do [with the seating] is just stay out of the way and not limit it. When I provide the supports needed for rest and fine-motor [activities], I don’t want that to be so much that it blocks gross-motor tasks.

“That’s how we prioritize the three goals. We’re always balancing those three, and they may fluctuate within the individual throughout their lifetime.”