Conquering the Slung Sling

Rigid vs. sling seating

by Kathy Wechsler on May 1, 2008 - 9:50am

QUEST Vol. 15, No. 3

Most people don’t want to sag as they get older. Why should their manual wheelchairs be any different?

Rigidizer by Varilite
MaTRx-Vi Cushion by Motion Concepts

This sling is slung

Jay Adjustable Solid Seat by Sunrise Medical
Contour Base by The Roho Group

Manual wheelchairs with both folding and rigid frames come with sling seating unless rigid seating is specifically requested for positioning purposes. When the wheelchair’s frame folds, some people prefer sling seating for the convenience factor. All they have to do is pull up on the sling to fold the wheelchair.

Sling seating doesn’t offer any positioning components and will begin to sway after a year or two of use, causing the user’s hips to rotate internally because they’re following the swayed upholstery. The result typically is hip pain, says Teresa Tisdell, an occupational therapist (OTR/L) at the MDA clinic at Integris Southwest Medical Center in Oklamoma City.

Because of poor positioning, the person may develop scoliosis or pelvic obliquity, where one hip is higher than the other, Tisdell says.

The “hammocked out” effect of sling seating also forces the pelvis into a sacral sitting position, meaning users roll back on their pelvis, greatly increasing the risk of lower back pain and pressure wounds on the tailbone.

The only reason for sitting in a sling seat is if you’ve been in one for many years and your body already is formed to that position. In that case, changing may cause pain and inability to function, and staying with a sling seat may be the only option.

“It’s very hard to make changes for a lot of patients,” Tisdell says. “Although a rigid seat may be the best positioning and [the wheelchair user] looks great, if they’re miserable in that wheelchair, it’s not doing anything for them.”

Tisdell argues that positioning at the pelvis always is more important than the back.

“I had a patient come in this last week with a rigid [wheelchair] back and a sling seat, complaining of back pain,” she says. “The problems didn’t start with his back, the problems start at the pelvis typically, so it’s important to get the pelvis correct and then move to the back from there.”

The best of both worlds

It’s not necessary to sacrifice seating and positioning for the convenience and portability of a folding wheelchair.

One possibility is ordering adjustable upholstery, so that when the sling seat starts to become loose it can be pulled back tight.

“You have to specify you want adjustable upholstery,” says Tisdell, adding that she still prefers rigid over sling seating, “even with all of the new improvements they’ve come up with.”

Another option is to replace the sling seat with a removable rigid seat. Usually made of plastic or aluminum, this type of seat is attached to the wheelchair’s frame by dropping it in place or by latching levers, and is removed by lifting it up or unlatching the levers. These types of seats also are used to lower the seat-to-floor height. Almost any type of cushion can be used with a rigid seat, which runs around $300.

Yet another option is to put a rigidizer, or solid seat insert, under the cushion inside the seat cushion cover. Rigidizers can be flat or contoured at the bottom and are made of molded plastic or an appleboard, a thin piece of wood.

Flat wood rigidizers work best with new wheelchairs with no sway in the sling, because the appleboard eventually will develop a curve if the wheelchair’s sling already is hammocked out.

Contoured rigidizers work best on older sling chairs that are “kind of swung out a little bit and you can fill in that space,” Tisdell says. “If you put a rigidizer that’s got a little bit of roundness to it on a sling seat that’s not yet hammocked out, it’s not going to fit very nicely.”

Rigidizers can be used under most types of seat cushions, and will slide right inside the cushion cover. This makes them easier to handle than solid seat inserts that are heavier and must be latched and unlatched. When folding the wheelchair, just take off the cushion and go, instead of unlatching levers and pulling off the rigid seat.

Rigidizers usually are priced from $35 to $75. Some cushions have built-in rigidizers.

We’ve got your back

Once the pelvis is in alignment, it’s time to give adequate support to posture.

Wheelchairs come with sling backs unless otherwise requested. As with sling seats, sling backs are bad for posture.

“With a sling back, you kind of cave down into it, which promotes scoliosis and can lead to potential surgery,” says Tisdell. A rigid back provides a firm surface that prevents this type of sagging.

Sling upholstery on the back of the wheelchair can be tightened, but experts agree that rigid backs are more reliable for many people with neuromuscular diseases.

A rigid backrest usually is made of plastic, wood or carbon fiber, with foam padding for comfort, says Rob Hails, general manager of United Seating and Mobility in Earth City, Mo. To remove the back to fold the wheelchair, flip the release lever on the quick-release mounting hardware and pull off the backrest.

Backrests cost between $400 and $1,500. Toward the higher end of the price spectrum, custom-molded backs are sometimes used for people with severe scoliosis. A custom backrest is made by taking an impression of the person’s back and may have cut-outs for laterals and lumbar support.

When shopping for a rigid chair back, focus on “comfort, support and the ability to minimize pressure issues,” advises Hails.

Think it through

Manual wheelchair users have several seating options from which to choose. When ordering a manual chair, typically the user, the therapist, and the equipment supplier sit down and talk about all the options — whether to go rigid or sling or this brand or that brand — and make decisions as the order is being prepared, says Tisdell.

She adds, “The more informed the consumer is, the more they can understand and ask questions.”

Aero Innovation Research, Inc.
(316) 755-3477

Freedom Designs
(800) 331-8551

(800) 333-6900

Motion Concepts
(888) 433-6818

Quantum Rehab
(866) 800-2002

The Roho Group
(800) 851-3449

Sunrise Medical
(800) 333-4000

(800) 827-4548

No votes yet
MDA cannot respond to questions asked in the comments field. For help with questions, contact your local MDA office or clinic or email See comment policy