Tilt: When, Why & How Much?
Posterior, Anterior, Lateral: Understanding the Many Functional Uses for Power Tilt
- By Laurie Watanabe
- Jun 01, 2020
DESCRIBE IMAGE: DEPOSITPHOTOS/IBRANDIFY
Power tilt is so common in today’s Complex Rehab
Technology (CRT) power wheelchairs that it can be easy
to take for granted. But tilt can be used for a number of
reasons and in a wide range of scenarios. And evolving
engineering capabilities also make it possible for CRT
power chairs to tilt in different
directions: posterior (rearward),
anterior (forward) and lateral
(side to side).
Mobility Management spoke
to CRT industry veteran Brad
Peterson, VP of U.S. Sales for
Amylior, about tilt’s functionality
for consumers who use CRT
wheelchairs, and how the use of
tilt has changed over time.
A Functional History of Tilt
There are many clinical and
functional reasons to add tilt to a
power chair, but it all started with
“Pressure reduction was, and
still is, king,” Peterson said. “That was why tilt first came
out: Pressure reduction without changing the hip angle
and adding shear to a system or inducing tonal reflexes.”
Today, tilt can support a number of goals.
“In my experience, I’ve seen it used for a lot of
different things and usually not just one,” Peterson
noted. “Respiration. Pressure reduction. Comfort is huge.
I’ve always been a firm advocate of ‘If someone’s not
comfortable, they’re going to somehow move themselves
into a position of comfort,’ which may compromise everything
you’re trying to do for them from a seating and
positioning standpoint. So they have to be comfortable.
“We’ve also used it a lot for visual field orientation: For
people with fixed open hip angles, a combination of
tilt and recline can get them to a more level view. Also,
transfers, environmental access, and van entry: People
getting into vans can be too tall, or the doors to short so
they tilt back a little bit. Environmental access is huge.”
Moving from a client’s head to the client’s lower
extremities, “A lot of times you have people who need
a very low seat-to-floor height or a very compact chair,
but they have interference with their front casters or they
have interference with something
up front,” Peterson said. “So they have to drive in 5° of
tilt for ground clearance or for
caster interference to still get
the seat-to-floor height or the
positioning they need.”
In fact, Peterson pointed out,
people who don’t use wheelchairs
often still like a bit of tilt.
“Most able-bodied people in
cars, if they have a power seat,
like to feel tilted back a little to
let gravity take a bit of the load
off of us, for head control and
That same tactic can apply
to power chair users, some of
whom are most functional and comfortable while sitting
and driving in a slightly posterior tilt position.
A Matter of Degrees
What has also evolved over time is the understanding of
what various ranges of tilt can accomplish.
“Over the years, we’ve said you need at least 45° of tilt
to elicit adequate pressure reduction, to offload the ITs
[ischial tuberosities] and the coccyx and move it somewhere
else,” “Peterson said. “It has also been said that
optimal pressure reduction occurs with a combination of
posterior tilt and recline. Our thinking is evolving based
on how often people are using their power positioning
and how useful prescribed functions actually are.
“There are some studies out there, not as many as
there should be, that show what an effective weight shift
or a pressure reduction is. But there are also studies that show that most people don’t use all the tilt they’ve been
prescribed. We have to look at why aren’t they using it? Is
it just non-compliance? Is it someone who doesn’t want
to be tilted that much? Is it someone who can’t, because
professionally or school wise or just personally, they can’t
spend 15 minutes an hour looking at the ceiling?”
The news that some consumers don’t use the full range
of tilt on their chairs has resulted in some funding sources
— notably, the Centers for Medicare & Medicaid Services
— deciding that larger ranges of tilt aren’t necessarily
needed and wouldn’t be as readily reimbursed. Peterson
believes the rationale was “Well, people don’t use it, so
we don’t need it.’ It’s kind of a slippery slope. Because I
think you do need a certain amount of tilt in a well-prescribed,
well-fitted, complete system for someone who
really has pressure concerns. Twenty degrees of tilt is
not going to do it. You have to have at least 40° to 45°,
or 30° in conjunction with recline. And that’s where your
clinician and your multi-disciplinary team to look at the
whole picture is so important.”
That being said, Peterson added, “For some people,
20° of tilt is fantastic. It might give them the visual field,
the balance, the stability that they need, or comfort.
From a manufacturing standpoint, it also opens up
possibilities for cost reduction; it opens up possibilities
for reducing the complexities for a chair. A lot of times,
if you’re only using 20° to 25° of tilt, you don’t need CG
shift. You don’t need that big, sliding, 45° tilt mechanism.
You can simplify a chair. It does have a cascading effect
on the design of a chair.”
It gets dangerous, though, for funding sources to
believe that lower ranges of tilt will work for everyone.
“What concerns me,” Peterson said, “is that some people
take advantage of a lower cost, and then we compromise
the code for the people who really need that 45° of
tilt for respiration, pressure reduction, etc.”
Tilt’s New Directions
Tilt no longer just means tilting backward. Anterior and
lateral tilt have given seating clinicians and providers
more positioning options to choose from.
“What I’ve found in my experience,” Peterson
explained, “is that anterior tilt is used a lot for transfers
and environmental access. We have a lot of people who use it just to put their feet on the floor for an assisted
caregiver transfer. For something like that, you don’t
necessarily need a big 45° of anterior tilt. You just need
something that will lower the knees in relation to the hips.
“I’ve seen anterior tilt help with tone reduction for
people who are hypertonic. If you put them in anterior tilt
and you align their shoulders over their hips, their tone
will actually decrease; they’re not always extending. And
it can also help with visual field orientation: Instead of
tilting them back, you tilt them forward.”
Part of the reason anterior tilt can facilitate environmental
access is what it does for a client’s ability to reach: “I think what a lot of manufacturers are doing now
is not just opening up the seat and back like a seat lift
chair and lowering the feet, but also bringing everything
forward. So you’re anteriorly tilting them, but you’re also
moving the whole seating system forward, and that’s for
things like reach and environmental access.
“So anterior tilt, especially now when you can do it
without adding a lot of seat-to-floor height, it’s comfort,
it’s pain reduction, it’s pressure. There are so many things
that anterior tilt can do.”
Peterson called himself “a huge fan” of lateral, or side-to-side tilt. “We all move in different planes,” he pointed
out. “So the ability to move yourself anterior, posterior,
laterally — I’ve seen quite a few people who could not
find comfort or could not reduce their pain or have
a sustained sitting tolerance by just posteriorly tilting.
They had to posteriorly tilt, laterally tilt, and just be able
to move and take pressure off their bodies and spines
throughout the day by moving in different directions.”
An Ongoing Evolution
The ability to move in different planes isn’t the only
factor of tilt that’s evolving. Peterson said that while
using recline with tilt had become extremely popular, it’s
becoming more common for clinicians to opt for tilt only
in some situations.
“They might do it because they want to simplify it for
somebody,” he said. “They might do it because they
don’t see an indication for recline. They might do it to
reduce complexity. There are a lot of reasons for doing
or not doing recline. It’s a solution, something you can
pull out of your toolbag and use based on someone’s
Tilt has become very common on power chairs, but
Peterson still advocates for a thorough assessment any
time tilt is being considered.
“When I first started in this industry,” he noted, “tilt
was a big deal. Now, it’s almost like ‘Everybody gets a
tilt chair.’ I’m not saying it’s mis-prescribed or over-prescribed.
I’m just saying sometimes people forget what
you have to look at with a tilt chair. Now you’re getting
systems with limited amounts of tilt, which may be perfect
for someone. But it also might preclude you from adding
to that chair in the future, and you have to look at things
like the environment and battery size and all kinds of
things when it comes to prescribing any power chair.”
And seating teams should also keep in mind that tilt
can initially be disorienting.
“So many times, I put a therapist into a tilt [chair], a tilt/elevator, a tilt/recline, who’s never been tilted. And they
grab onto that armrest like they’re about to go over,”
Peterson said. “So you have to make sure that [clients]
try it, because a lot of times, I think the reason you’re not
seeing compliance is because of fear.
“Fear, lack of stability — a lot of people are getting
out of their comfort level, especially people with tone.
For people with cerebral palsy, fear and stability are
big things you should assess for when you’re adding tilt.
That’s why a lot of the electronics that people have now
allow you to do things like proportional actuators, where
you can tilt back at your speed instead of just being at
one speed. You can limit how much tilt they have until
they get comfortable. You can ease someone into it.”
As common as tilt is, Peterson said it’s not an option
that should be automatically applied to every client.
“We try to paint it with a brush,” he said. “But it’s
different. Rehab is not black and white; it’s very gray.
And using tilt depends on dozens of different things on a
“Tilt, while considered the simplest, most ubiquitous of
power positioning functions, brings with it many things to
consider, clinically, functionally and environmentally. We
must not overlook the function and independence it can
unlock, keep exploring and asking questions.”
This article originally appeared in the June/July 2020 issue of Mobility Management.