One of the biggest challenges
therapists and providers
have is matching the correct power base
to a consumer’s needs. The team needs
to consider the activities of daily life the
person will use the power base for and
what environments and challenges the
wheelchair must overcome in order to
meet the everyday use of the consumer.
One of the worst outcomes from evaluations
are consumers becoming dissatisfied with their power wheelchairs
because the chairs don’t meet their
needs, don’t fit into the transportation
they use or don’t fit through the many
different doors they must go through on
a daily basis. It is very easy to miss one of these important factors.
We need to be very thorough in every evaluation we perform to
be sure that all the consumer’s needs are explored and evaluated.
The best approach to evaluation for a power base is to educate
consumers so they alone or with their team can make an educated
decision on which power base meets their needs the best.
There are many things to educate consumers on throughout
the evaluation process. The list includes drive-wheel configuration,
accessories and seating components that are needed to
meet their needs. Each of these items is impacted by the environmental
and functional needs the individual has.
Drive-Wheel Configuration
Each drive-wheel configuration comes with its own set of advantages
and disadvantages. Consumers will often decide what is
an advantage or disadvantage specifically to where they use the
wheelchair.
For instance, if consumers have a fully accessible house with a
very open concept floor plan, then turning radius may not be an
advantage or disadvantage for them because any of the drivewheel
configurations will work in their home environment. But
as the evaluator, we really have to examine things with a broader
view. Although their home environments may be very accessible
and easy to maneuver around, what happens when they go out
into the community?
When evaluating for drive-wheel configuration, we need to
look at consumers’ multiple environments, including inside their
homes and all of the other environments where the wheelchairs
will be used. These environments may include home, indoors
and outdoors, work, school, the grocery store, mall, vehicle used
for transportation (private and public), and other locations they
may venture into. Many of these environments may have different
types of terrain the wheelchair must handle as well.
In order to look at each drive-wheel configuration during an
evaluation, the evaluator must have a good knowledge of what
the pros and cons are of each.
Front-Wheel Drive
This drive-wheel configuration is known for having a tight turning
radius for maneuvering around corners, but consumers must
be aware of the rear part of the wheelchair because it needs
to swing as they are making the corner. Front-wheel drive also
climbs obstacles very well because the larger drive wheel is in the
front of the wheelchair.
If consumers have tight hamstrings and their legs need to be
positioned tight to the seating and wheelbase, front-wheel drive
is ideal because this drive-wheel configuration does not have
front caster wheels, allowing for greater ease with positioning the
legs closer to the power base. If you have a person whose center
of gravity needs to be positioned forward on the wheelbase,
front-wheel drive can be a very stable platform because his or
her weight is being placed over the drive wheels, which will assist
with traction while driving.
Mid-Wheel Drive
This drive-wheel configuration is known to be useful for
consumers with very tight spaces in their homes and who have
the need for good maneuverability. A mid-wheel drive power
wheelchair can turn in a 360° circle using only the footprint of the
wheelchair (from the consumer’s feet to the rear caster wheels).
This allows maneuverability in very tight, confined spaces.
This drive-wheel configuration tends to be very intuitive for individuals
who have previously been ambulatory, because the midwheel
drive wheelchairs drive much like we walk. These days it is
very common to have a six-wheels-on-the-ground design, as that
provides the consumer with very good stability while driving. When
it comes to outdoor use, mid-wheel drive tends to track across a side
slope very well, as the drive wheel is in the center of the power base.
Rear-Wheel Drive
This drive-wheel configuration is best known for having tracking at
higher speeds. These power bases will track very straight with the
least amount of fishtailing of any of the power bases. This drivewheel
configuration also handles aggressive terrain very well due to its larger front caster wheels. For stability in a power base, rearwheel
drive provides very good stability. Many users who drive
with non-proportional input devices find rear-wheel drive the
easiest to control, so it can be very much a personal preference.
Again, each drive-wheel configuration has its own advantages.
Many of the advantages and disadvantages need to be discussed
with the consumer for the consumer to make the best-educated
decision as to what drive-wheel configuration is most important
to his or her daily routine.
In addition to drive-wheel configuration, manufacturers offer
different components to their power bases to enhance their
performance.
Some of these additional features include suspension, higherspeed
motors, tracking technology, larger caster wheels and
electronics. Each of these additional features lends to the overall performance of the power base and will be more important to
some consumers than others.
And What Will Happen in the Future?
When choosing a power wheelchair base with a consumer, we
not only need to consider the environment and what the drivewheel
configuration provides, but also what the consumer’s
future may hold in store.
Is his or her diagnosis progressive, or is he or she expected to
remain stable? These factors will influence decisions regarding
expandable or non-expandable electronics and whether the
power base may need to accept a power seating system for
positioning, pressure management and management of other
medical needs.
Choosing the correct mobility base is a very big decision, and
whatever is chosen must meet the consumer’s needs for many
years to come. It is a decision that we as therapists and ATPs have
influence over, but our true job should always be not to decide
for consumers, but to be sure they have been properly educated
in order to make the best informed decisions for themselves.