ATP Series

Positioning the Extremities

How Supporting Arms & Legs Can Yield Great Functional Benefits

• By Laurie Watanabe
• Oct 01, 2021

If the pelvis is the foundation of functional positioning in a wheelchair, then how do the upper and lower extremities impact optimal positioning?

“The arms are so important,” said Gabriel Romero, VP of Sales & Marketing for Stealth Products. “People always go straight to the pelvis, but a lot of other things dictate what the pelvis is going to do. The arms are like wide pillars — they [can be] folded in front for good frontal support, or pushed to the side so they can give good lateral support. You really have to figure out what’s the best solution for them.”

Failure to optimally position the upper extremities, Romero added, can lead to other positioning problems. “I’ll see a non-funded or a more basic chair, and I’ll see the person’s kyphotic positioning just due to armrests not able to be adjusted, or arm pads not being wide enough. When adults start losing strength, or children don’t have strength, they’re going to go wherever their arms take them. You’ll start to see shoulder dipping, you’ll start to see head tilting because an armrest’s height or length or width wasn’t considered. A tray platform wasn’t considered. It’s a ripple effect.”

Upper-Extremity Positioning Goals

So what are the priorities when positioning a wheelchair user’s upper extremities?

Tina Roesler, PT, MS, ABDA, is Director of Clinical & Business Development at Bodypoint.

“It depends on the client,” she said. “If I’m looking at someone to drive power controls, for example, I’m going to look at what maximizes their stability so they can still use what function they have to reach the joystick or manipulate the joystick, and what position helps them maintain that. Say they have tilt in space or recline: You don’t want them to lose that position when they tilt the chair back so they can’t reach the joystick to untilt, for example.

“I think we’ve done better at looking at that and discussing that. I think with some of the higher levels of [spinal cord] injury that need total arm support, I think we’re doing much better.”

The priorities are much different, Roesler said, for clients using ultralightweight wheelchairs: “When you start thinking about someone who’s self propelling, it’s not necessarily positioning per se of the upper extremities, but the position of the shoulder and the upper extremity relative to the chair and the rest of the body. So basic biomechanics come into play. While we might not be positioning them statically, we want to be sure the shoulders are in a more neutral position, and that there’s not too much external rotation or extension happening during propulsion. All of that comes into play when you start talking about the trunk and the pelvis. You’re reducing repetitive stress and strain by having the best biomechanics at the upper extremity.”

The stability and positioning of the trunk and pelvis directly impact upper-extremity function, Roesler said.

“I’m sure you’ve heard the old adage that proximal stability promotes distal function,” she explained. “So I think that’s why there’s so much focus on the pelvis and trunk: If I don’t have that stabilized, I can position the arms the best that I can, and [clients] still might not be able to function with their upper extremities properly.”

A stable pelvis and trunk, she added, allows the wheelchair user “to initiate control, to initiate movement at the upper extremity without falling over or being in an awkward position.”

And even when the arms aren’t being used to propel or operate the wheelchair — for example, with dependent mobility, when a caregiver is pushing the wheelchair — those upper extremities still need to be supported, Romero added. If arms are left unsupported, “Now we have to talk about shoulder pain management, because for the longest time, somebody’s arms might have been hanging, unpositioned. So now you have joint pain.”

Lower-Extremity Positioning Goals

The need for functional upper extremities seems pretty obvious: Arms and hands perform many activities of daily living, and they often operate the wheelchair and seating functions. But why is lower-extremity positioning so important?

“That’s one of my pet peeves, when I see someone come into a seating clinic or I watch them in a wheelchair and they don’t have their feet supported,” Roesler said. “I can do as much positioning as I want to with the trunk, the pelvis, the upper extremities: If my lower extremities aren’t supported, I no longer have that closed chain.

“I always use the term closed kinematic chain, which is a biomechanics term. When you’re seated with your feet supported — your trunk and your pelvis, all the way down to your feet and all the way up to your head acts as one closed chain or one unit. Whatever I do to one of those segments impacts the other segments. If my feet are dangling and pulling me forward, it impacts my entire trunk, my entire pelvis, my entire head, my upper extremities and my ability to control all of that.”

Footplates often get a bad rap: Depending on their placement, they can add to a chair’s length and raise the risk of running into walls during turns. They can get in the way during transfers.

Still, eliminating the footplate usually isn’t the best option.

Roesler said she’s “never [heard] a good explanation” when a footrest is missing from a wheelchair. “Maybe it was easier for the caregiver, and they didn’t realize the implications from a postural standpoint,” she said. “If my feet are dangling and my legs are dangling off the chair, it changes my postural position. It tends to pull me into a posterior tilt. It can also cut the circulation off at the back of your legs.

“Dangling feet are going to affect everything else you tried to do in the rest of that chain. It’s a closed chain as long as your feet are supported. Once you open up that chain, it’s like a noodle: shear, friction, posture abnormalities, posterior tilt. It can cause permanent postural abnormalities, like permanent plantar flexion or rotation. And then you have even a more difficult time when you try to support the lower extremities.”

Roesler pointed out how uncomfortable high barstools can be when legs dangle for any length of time. “Are you comfortable in that position?” she asked. “The only time I would ever say that dangling feet are okay is if someone, for example, has a severe pressure injury on the bottom of their foot. Other than that, the feet should always be supported in some way for stability.”

Building Movement Into the Seating Strategy

One of the challenges of positioning extremities is that wheelchair users move — intentionally as well as unintentionally — within seating systems. They reach and lean when performing daily activities or operating their chairs. They can also experience tone and spasticity that moves them within their seat.

That’s why extremity support is particularly important, Roesler said. “Especially when you have someone with tone, they need to be supported at their feet, but also supported correctly so it doesn’t initiate more tone, say, when they go over a bump,” she said. “That’s where you see more use of secondary postural supports: With a lot of pediatric clients, you see the use of ankle huggers to help keep their feet in place. Or a calf support, either posterior or in front of the lower extremities, can really help while the person is trying to function. So maybe their tone doesn’t negatively impact what they’re doing, and maybe they can utilize their tone to help increase function as well.”

Some wheelchair users actually use their tone to perform activities. “You’ll see a lot of people initiate their tone increases, and sometimes that helps them do functional tasks, like driving a power chair,” Roesler said. “You might see their tone increase in their lower extremities as they try to reach the joystick, for example.

“When I first started in seating and positioning, it was You want to control the tone and stop it. As we’ve learned more and really looked at what we’ve been doing, we’ve realized that sometimes that tone that might be abnormal is helping them do some activities. We want to minimize the negative impact of it, but we don’t necessarily always want to eliminate it.”

That’s when dynamic postural supports can be helpful.

“I think that’s where secondary postural supports are different than seatbelts, for example,” Roesler said. “A lot of [Bodypoint’s] chest harnesses have a dual stretch so that they stretch when they need to. If you need to lean forward, you can. But because of the stretch, it’s also going to help you return back, because it does want to return to its original position. It’s not like a spring; it’s not that strong. But it gives you enough movement to be able to use your upper extremities or move within a range and then help you come back to the original resting position.”

Roesler added that dynamic supports can be adjusted per each client’s needs: “You can make a postural support be pretty tight and not have a lot of dynamic motion, but it’s always good to have a little bit. You don’t want so much that the pelvic belt or chest harness starts to slip, because that can become dangerous over time. But you do want it to have some motion. Even the type of buckle you use can impact how much or how little motion you get, depending on the configuration.”

Dynamic supports can be particularly useful for pediatric clients. “The example I always use is for kids,” Roesler said. “A lot of times we’re using postural supports with kids because one, we do want them to be safe. But we also want to give them some postural support. We also know they tend to move around a lot more, so we don’t want to restrict that too much.

“We have a [Bodypoint] swivel buckle that allows the harness or belt to move laterally and rotate a little bit as the person moves in the chair. So it still has a firm hold and tries to keep your position, but it allows some movement in different directions, whereas a straight rehab latch or push-button buckle is pretty much fixed. You’ll still be allowed a little movement from the stretch in the belt itself, but it doesn’t move with you. So it may not be as comfortable, and if you have someone who’s asymmetrical, it may not be as comfortable, either, because it might not distribute pressure the same way.”

Adapting Strategies to Get the Best Function

That’s the greatest challenge for upper- and lower-extremity positioning: Each client needs a unique approach.

“Especially when it comes to driving a power chair for an individual with cerebral palsy — maybe they have to elicit tone to reach the joystick,” Roesler said. “It may not be normal, but they’ve developed it for function. Sometimes if we apply too many postural supports or correct it too much, we take that away.

“I’ve seen that happen before: ‘Oh, look how nice and straight they’re sitting, and they have this nice belt and chest harness.’ And now they can’t drive their power chair for some reason. So it’s really important to look at that and realize tone isn’t always a bad thing. Some people have learned to live with it and make it useful for them. You don’t want tone to be so strong that it’s causing postural deformities or limiting what someone can do. But that’s where postural supports come in. If I have someone who has a lot of lower-extremity tone when they push a manual chair, for example, maybe use an anterior support on the lower extremities or a good pelvic positioning belt. Although they still might get tone, the belt helps them maintain lower-extremity position so they can still propel easily or more easily.”

Romero praised seating teams who take the time to fine-tune postural components for each client: “There are great ATPs that take their time and get adjustable armrests that can rotate in if they need to, or troughs that can rotate in. Sometimes it’s for comfort and positioning. It becomes critical for them because now they can be in their chair longer, which again is the ultimate goal for everyone.”

This article originally appeared in the Seating & Positioning Handbook 2021-2022 issue of Mobility Management.