The benefits of posterior tilt are many and well known
— important enough for the Rehabilitation Engineering & Assistive
Technology Society of North America (RESNA) to disseminate a position
paper affirming its usage, and familiar enough that it’s common
for the industry to refer to posterior tilt as merely “tilt.”

But other forms of tilt are now increasingly available, particularly
on power wheelchairs. And having a combination of tilt options can
help seating & mobility clinicians and ATPs to dial in just the right
positioning combinations for their complex clients.

The Job of Posterior Tilt

Posterior or “backward” tilt is largely used to enable a wheelchair user
to weight shift for pressure relief, which can help to keep skin and other
tissues healthy, though Diane Beckwith, MS, PT, Emory University
ALS Center, said she’s used posterior tilt “in my clinic just as often if
not more for postural control. Gravity assistance is used to help clients
reposition for midline alignment; pelvic alignment to the rear of the
chair for posterior pelvic support and proper back support; and to align
body and legs mediolaterally.”

Among other benefits of posterior tilt, Beckwith also listed rest,
blood pressure and autonomic dysreflexia management, and using the
gravity assist provided by posterior tilt to help with functional reach
and exercising shoulders and other joints.

Joe McKnight, ATP/SMS, director of clinical development for
Superior Mobility, said of posterior tilt, “Tilt is a tremendous tool for
reduction in pressure. The biggest reason we use tilt is for body position.
It helps reduce tone, it provides sensory input, eases breathing,
manages tone and thrust, provides for gravity repositioning, helps
with swallowing and secretions, helps rearward reach. There are a lot of
reasons we use tilt.

“From best practices in posterior tilt, we know that there is no substitute
for changing position. No cushion, no other process is a substitute
for changing position. Human beings change positions, studies say,
about 7.8 times an hour. So the best recommendations that have come out say that people should be changing position about eight times
an hour, and the use of posterior tilt back to optimally 45° to 50° will
optimally reduce pressure on patients significantly.”

McKnight added that due to an abundance of literature on posterior
tilt, “Now it is fairly regularly funded by most payors. The funding literature
is consistent: It’s consistent in Medicare guidelines, it’s consistent
among almost all payor groups. If somebody is at risk for pressure sores,
if they need chronic repositioning, if they’re not able to reposition themselves
for one reason or another either on manual or on power, you can
usually get posterior tilt.”

Anterior Tilt Possibilities

The other forms of wheelchair tilt — anterior and lateral — have not
been as commonly used as positioning options to this point in time.

Anterior tilt moves the wheelchair user forward in the seating
system. Lateral tilt moves the user so he/she is leaning either left or right
in the wheelchair.

So the first question about these “other” tilt functions is this: Do they
typically relieve pressure and weight shift the same way that posterior
tilt does?

“No,” Beckwith said. “It is well understood that an effective weight
shift is around the 50° mark. Lateral and anterior tilt do not tilt to that
degree. The extremes of anterior or lateral tilt are generally in the 10° to
20° range.”

So if the primary goal of lateral and anterior tilt is not weight
shifting, when might they be beneficial seating options?

For anterior tilt, Beckwith said, goals could include “to promote
righting reactions or more of an anterior tilt of the pelvis, and transfers
made easier by allowing the client to slide anteriorly easier. Also to
increase clearance under tables.”

McKnight has successfully used anterior tilt to address center-ofgravity
issues with bariatric clients.

“For some of our obese patients, that becomes an important thing,” he
noted. “Where you’re putting the center of gravity in that chair and how
they’re loading and unloading into that chair. Those become important
considerations, too. Maybe I want to use some anterior tilt and load the
center of gravity a little bit farther back because I’ve got an obese patient
who’s going to be really forward loaded. So as they’re sitting in the chair, I
know they’re already going to forward load. So I’m going to go ahead and
change the center-of-gravity point as to where that’s going to be. I’ve got
to change the pivot point.”

Anterior tilt can also be helpful for very young clients.

“There are some studies that have come out,” McKnight said, “that
seem to indicate that if you can use anterior tilt with children, it improves
vestibular development, and that it develops core trunk muscular development.
We know that placing a child in mild anterior tilt and having
them work against the tilt for short periods of time — five to 10 minutes
or so — and then putting them back in posterior tilt really helps them to
develop core strength and vestibular response. It also helps them develop
some functional reach.

“Certainly for adults, we know that using anterior tilt can help with
transfers. So there are a number of good reasons there, and a number of
[wheelchair and seating] manufacturers offer it now.”

Lateral Tilt Applications

Lateral tilt — using the seating system to shift a client either to the
left or right — “is used for correction of a scoliosis or lateral trunk fall
reactions that cannot be corrected with the seat cushion or backrest,”
Beckwith said.

McKnight said, “Lateral tilt is kind of an odd one; you don’t use
lateral tilt a whole lot. But the indications for lateral tilt include stroke
patients that are persistent leaners — chronic leaners that are wanting
to push themselves over because they develop vestibular issues. They
develop balance issues as a result of stroke.”

Trying to prop up these clients with cushions, wedges or homemade
solutions such as rolled-up towels or blankets isn’t likely to work, he
added. “You’re not going to correct them with a lot of lateral support. It
doesn’t matter what you use as far as providing lateral support. Lateral
tilt seems to be kind of your only means to [address it].”

Lateral tilt could also be helpful for some clients having trouble
performing activities of daily living (ADLs).

“There are also some functional reach things that you can do with
lateral tilt for some of these people,” McKnight said. “They may have
ADL issues, so lateral tilt becomes a functional need for them. You’ve
got to kind of figure out where you want to put the pendulum and what
they want to do.”

While both lateral and anterior tilt could, in theory, provide some shifting of a client’s weight, McKnight points out that the sheer
physics involved in those forms of tilt make it difficult or impossible
to achieve the ideal and optimal pressure relief that posterior tilt
routinely provides.

“It’s difficult to get somebody to stay, say, 30° over [to one side],” he
explained. “Thirty degrees is the National Pressure Ulcer Advisory
Panel guideline. But think about yourself being able to pivot over 30°
in order to get pressure off of an ischial tuberosity (IT). That’s a lot of
lateral tilt, and how are you going to hold yourself in the chair at 30°?
How much are you going to have to build up that side of the chair in
order to tilt somebody laterally 30°? Are you going to combine that
with posterior tilt in order to hold them back into a corner and hold
them there, in order to completely unload an IT like it’s supposed to?
That’s an awful lot of expense just to offload an IT. Probably the only
place I can think of that I might do something like that as far as an
application is if I had somebody who has had a hemi-pelvectomy, and I
had to completely offload one side of a pelvis.”

Great Options to Have

Though anterior and lateral tilt don’t currently reach the same volumes
of clients as posterior tilt, McKnight said they are becoming increasingly
available, either through a power chair or power seating manufacturer’s
production offerings or via the manufacturer’s custom department (see
sidebar). So it’s worth asking about if you do find yourself working with a
client with a unique set of needs.

Beckwith confirmed that adding anterior or lateral tilt to a wheelchair
with posterior tilt could be done “to achieve all of the above
benefits in combination [for] someone who has multiple needs.”

McKnight agreed that the need for these “other” forms of tilt is relatively
rare. At the same time, seating & mobility team members who
choose to use lateral or anterior tilt may find that nothing else works as
well for that particular client.

“The biggest thing that I’ve seen lateral tilt used for are my lateral
leaners that are really way far off on one side and continue to put
pressure on one side a whole bunch,” McKnight said. “So I use the tilt to
compensate for that vestibular orientation.

“They are bent on going in that direction, and the only thing that
we’ve been able to do is use lateral tilt in order to reorient them. Or if
I’ve got somebody with a strong neck tone that is turned in that direction,
and I’ve got to straighten them out.”

He recalled a client “with scoliosis so far over that we literally tilted
the base and then straightened the back to accommodate that much
scoliosis. The base of the chair itself was tilted. We accommodated
almost all of that with the cushion, almost 6″ of obliquity. In a sense,
that’s literally lateral tilt that we built into the cushion and base. That
was more of a permanent lateral tilt that we built in.”