Page 281 - Handbook of Electronic Assistive Technology

270 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

• Lifted transfer – person lifting may wish the seat to be higher up.
• Lower leg length in relation to footplate height from the ground(i.e., a tall person may
find that the footplates are too close to the ground to allow passage over undulating or
rough terrain).
• Ability of the chair to fit under a surface (i.e., dining table, desk, kitchen worktop/
counter, etc.).
• Where specialist seating is to be used, a lower wheelchair seat height may be desirable
because the bulk of the seat may push the person higher than normal.
• Social interaction – if a seat riser is not fitted, the person may prefer to be set at a
higher position.
• Access into and within a vehicle – the height of the aperture of the access door and
height available within the vehicle may govern seat height.
• Where the occupant has tight hamstrings (with the hips flexed, knees are unable to
straighten to any less than around 90 degrees of flexion) the feet are set back and are
likely to clash with the castor wheels, meaning that the footplates may have to be
positioned above them, which will influence seat height.

Dimensional information can usually be found in manufacturers’ product literature,
but with the number of variations in specification that are available, it can become neces-
sary to perform a physical check on a demonstration model. Additionally, the type and
shape of the seat cushion coupled with the design of the chair seat frame will need to be
considered because it is possible to ‘sink’ a cushion into some frames, whereas this cannot
be achieved with a flat seat pan.
It should be remembered that adding powered functions will usually add to seat height
due to the additional mechanical bulk.

Drive-Only Powered Chair
Many powered chairs still offer a simple drive-only capability, and for a large proportion
of wheelchair users this will be suitable and acceptable. If it is to be a first powered chair
to allow greater independence outdoors and to enable coverage of longer distances than
is practical or realistic in a manual chair, then a drive-only chair will often be the most
appropriate based on cost and ease of use. These chairs will benefit someone who has
reached the stage where a manual chair, and maybe a scooter, are no longer viable options.
The person will:
• Usually be able to perform an independent transfer.
• Be able to drive the chair with good control via a standard joystick.
• Likely be someone who is not a full-time wheelchair user, or might be someone who
uses a manual chair and a powered chair for different activities, choosing whichever is
the more appropriate to the task in hand.
• Be less likely to have postural needs and will be capable of sitting without support in
an upright position for the duration of the time they need to use the chair.