Page 288 - Handbook of Electronic Assistive Technology

Chapter 9 • Powered Mobility 277

Powered Seat Height Adjustment

There will be many potential lifestyle and social benefits to the provision of a seat height
adjustment, both in and out of the home. As stated earlier, most chairs with this feature
focus on increasing elevation away from the floor, but one or two have the capability to
descend in height, which is particularly suitable for young children needing to be among
their peers who might be playing on the floor or sitting on a mat in class. The following
benefits may be derived:

1� Increased access to differing environments.
2� Reduction in the need for housing adaptions.
3� Improved social interaction with peers as users can get closer to eye level, which may
result in empowerment and greater independence.
4� Compensation for weak arms in lifting/moving items.
5� Aids a standing transfer with some conditions (e.g., Becker muscular dystrophy, where
the person does not have the strength to lift their weight from sitting to standing).
When a seat is raised to an optimal height the person is able to slide forward and drop
down with legs already extended; this can significantly increase independence and
reduces the needs of other equipment for transfers, such as a hoist (4th International
Interdisciplinary Conference, 2010).

The following considerations should be made when selecting this feature:

1� Increased cost (usually).
2� Increased weight (although this is less significant for a powered chair).
3� Increased seat height due to additional mechanism which, while being beneficial to
some, may hinder others.
4� Risk of entrapment to younger children (fingers and limbs).

Standing Function

Chairs with a standing function have the potential to provide many physical, social
and psychological benefits to the user but they can be bulky and heavy, which can
cause problems both environmentally and for choosing a suitable vehicle. Some ramps
and smaller through-floor lifts have weight restrictions, which may impose a barrier.
Seeking informed and impartial advice prior to purchase is essential as chairs can vary
significantly in specification and operation, despite what the literature might suggest.
The bald fact of the significant price increase over the majority of nonstanding chairs
is a barrier to ownership for many people. However, the following benefits may be
derived:
1� The person can stand spontaneously (usually) and frequently through the day, to fit in
with their schedule.
2� Some chairs offer sit-to-stand whereas others provide lie-to-stand; this choice will be
determined by the circumstances and physical condition of the person.