Page 18 - Mobility Management, May 2019

ATP Series
Stability at the Core
to prevent any kind of posterior sacral sitting and the posterior tilt of the pelvis, so you try to correct that with the design of
the cushion. But you’re also looking for skin protection. You might build up the laterals a little bit on the sides and maybe the abductor to keep that person stable with the pelvis.
“But what you need to do also is have that back support. Even at that sacral level, that back system should be having contact. Where’s the scapula contacting, and do they need that scapular contact or not? Because if they have a better core, you may be able to open up that scapula so they have more function of the upper extremities. That even applies to power, because they need their upper extremities for the controller if they’re still using a hand controller.”
Components for Core Stability
Sayre said she tries to create as much stability as possible using
a positioning cushion and a contoured back; for example, she likes trying a deep contoured back — one that wraps around the sides — before trying positioning components that add weight to the chair and can also potentially hinder transferring in and out of the chair.
But for some clients, the positioning offered by the seat
cushion and the backrest aren’t enough support. That’s when adding a carefully considered set of positioning components can help.
“Core stability starts with accurate and carefully selected wheelchair seats and backs as the base of support,” Kosh said. “But since gravity alone is not enough to keep the person from shifting, a good belt applied in the right position can make a world of difference.
“Belts should be fitted according to the user’s individual needs, but a good starting point in most cases is worn across the thighs, with the belt pulling at about a 70° to 90° angle from the seat. This position is more comfortable for the wheelchair user than when mounted across the lower abdomen or hips at 45°. It is also more effective in helping to keep them engaged with the seating system to maintain core stability and benefit from the available support below the thighs and ITs [ischial tuberosities], as well as against the PSIS [posterior superior iliac spine] and lower back. By helping to maintain a favorable posture, sitting tolerance is increased, reducing the onset of normal daily fatigue.”
As the next step, Kosh said, “If the trunk is not stable after mounting the right belt in the right position, then anterior and lateral trunk supports should be considered. There are many
The Mathematics of Tilt & Weight Shifting
Studies have shown that users of complex rehab power chairs regularly use tilt to change their position, usually to feel more stable or comfortable. What’s more of a challenge is getting those users to use enough tilt to effectively weight shift to alle- viate pressure.1
Consumers who have less inherent core stability often choose to sit in a position that includes a small amount of tilt. For example, sitting while tilted back 10° becomes their new normal because that position allows gravity to more substantially assist them with staying upright.
Jean Sayre, MSOT, ATP, CEAC, VP of Research & Clinical Development for Quantum Rehab, agreed: “There are a lot of people who are permanently in a 5° to 10° tilt while driving.”
These power chair users can run into problems if they don’t consider that tilt amount when deciding how much to tilt to
shift weight and relieve pressure. For example, a user might be advised by his clinician to tilt back 45° to relieve pressure — but that number assumes that the user is starting at 0° of tilt. If the user is already tilted back 10° for comfort, then tilts to a total of 45° to relieve pressure, he’s actually only netting 35° of tilt, which is less than what his clinician recommended.
To accommodate those users’ preferences while still making
it possible for them to tilt effectively to relieve pressure, Sayre suggests advising clients to “come back out of that 5° to 10° tilt
if they’re just sitting on a flat surface and not driving. If they’re watching television or working, just come out of tilt and sit upright.”
Doing that means that clients will start at 0° of tilt, so that when they tilt 45° to relieve pressure and redistribute weight, they are in fact tilting the recommended 45°.
The fact that so many power chair users do prefer to normally sit and drive with some degree of tilt is one reason that Sayre is a proponent of anterior (forward) tilt.
“It’s not just for transfers,” she said. “If you need a forward [seat] slope, if you need to tuck your pelvis forward, with [anterior tilt] you’re extending your spine and changing your position.”
Going into even a small degree of anterior tilt again changes the posterior tilt math. Instead of starting from zero and tilting back, for example, 45° posterior to weight shift, a client would only have to do a posterior tilt of 35° to still net a 45° weight shift if he starts out from a position of 10° of anterior tilt.
Since many power chair users notoriously dislike tilting too far back, using anterior tilt in conjunction with posterior tilt might be a way to improve compliance while requiring less posterior tilt.
“In powered seating,” Sayre said, “some people only use
tilt. I like using tilt and recline to open up those hip angles and
to change the hip angles. It’s just [a matter of] changing body positions. We change body positions naturally, and we don’t even think about it. Just in 30 to 60 seconds of sitting, think about how much you shift in your chair.” m
Source: (1) Mobility Management, “Tilt by the Numbers,” Feb. 2014, http://tinyurl.com/tiltbythenumbers
18 MAY2019|MOBILITYMANAGEMENT
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