Special function wheelchairs are some of the more unusual chairs that have been developed with features to suit users with particular needs that are not met by the standard range of self-propelled or carer assisted chairs.
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Active user wheelchairs
Wheelchairs for a lower limb amputation
Wheelchairs with an elevating seat
Wheelchairs with a reclining backrest
Wheelchairs with a tilt-in-space seat unit
• Active user wheelchairs
These were originally designed for use in sport, but as they are very light and adjustable, they can suit older and frailer users who find a standard wheelchair hard work.
• Key features include: frames that are available in a range of sizes; quick-release wheels; multiple axle positions; rear wheels that can be moved forwards, which means that the chair can not only be propelled with much less effort, but the front castors can also be lifted from the ground more readily, making it easier to negotiate kerbs and other obstacles.
• Cambered wheels – wheels that are set at an angle to the vertical make it easier both to steer a straight course, and to turn the chair. A camber of up to 5° gives the benefit of easier manoeuvrability, without making the width of the chair so great that it become difficult to get through doors and narrow passageways.
• Backrests on active user wheelchairs may be lower in height than on standard chairs, providing just enough support for the lumbar region, while leaving the arms completely free to propel the chair without hindrance. Some active user chairs have an angle-adjustable backrest, for greater support.
• Materials – aluminium alloy is much lighter than steel, although a bit more expensive. Greatest lightness and strength is provided by carbon fibre or titanium, but these materials are a lot more expensive, and can be hard to repair – although they won’t corrode
• Lever-propelled wheelchairs
As their name suggests these chairs have a hand lever on one or both sides which the user push and pull in order to propel the chair forward and steer. The two lever design allows the user to build up more momentum by push and pulling each lever alternatively.
Similarly to one-arm-drive wheelchairs this design requires more strength and coordination than a standard chair. Rough ground and slopes are difficult to negotiate. Finally brake lever extensions might be required for the ‘weaker’ side
• Wheelchairs for someone with a lower limb amputation
Amputation of all or a part of someone’s leg means that their centre of gravity will be modified. In consequence, this means that they might tip over backwards in a wheelchair.
To get proper balance, a wheelchair with its wheels set further back is needed.
• Wheelchairs with an elevating seat
The seat height can be adjusted so that the user can reach higher levels, to access high shelves, or achieve eye level contact with able-bodied people.
On some designs, the seat can be angled so as to help the user stand up. This is done by a powered or mechanical mechanism lifting the back of the chair to allow the user to place his feet flat on the ground.
It is possible to replace the existing seat so that a normal wheelchair can be adapted. Once again, this mechanism adds a significant amount of weight to the chair.
• Low-seat wheelchairs
These wheelchairs are designed to enable the user to propel and steer the chair using their feet. However, this type of chair tends to be heavier, so a lighter, attendant-assisted chair might be a better choice.
If only one foot can be used to propel the chair then one footrest will be required and maybe an extra support to stop the foot slipping sideways. No footrests are required if the user uses both feet for propulsion.
Both feet need to be positioned firmly on the floor to help manoeuvrability. This however, inhibits good posture and compromises may need to be made to stop the user slipping forward, such as a trunk or pelvic support.
If the chair is mostly for indoor use then a castor type chair is a good idea. This design has a low seat and is lighter than a standard wheelchair.
• Comfort wheelchairs
The term “Comfort Wheelchair” is a fairly general one, used to describe wheelchairs which are more comfortable than standard. The added comfort comes from extra padding and contours, and sometimes a reclining feature. The added comfort is to the detriment of the manoeuvrability of the chair as there is extra weight involved.
Comfort wheelchairs are especially useful for people whose disabilities are not accommodated by standard wheelchairs
• Wheelchairs with a reclining backrest
This feature is useful for –
• anybody who has weak muscles in the upper body or a stiff spine or hips and cannot sit up.
• anybody who cannot stay in the same position all the time.
• anybody who has trouble breathing.
• anybody who, because of their treatment, needs to be in a reclining or semi-reclining position. The user must also bear in mind that some chairs only offer a semi-reclining feature.
With the chair in the reclined position and the legs elevated the chair is very long and therefore unwieldy. The space in the house needs to be taken into consideration for manoeuvring such a chair.
• Even if they are equipped with self-propelling wheels, these chairs are too heavy for the user to propel and so will need someone to push them.
• In the reclined position, negotiating kerbs is almost impossible.
If the reclining mechanism can be user-operated, the user will need to have good upper body strength because this design requires the user to sit up before moving the backrest. If it is carer operated, you need to check whether the user has to get out of the chair before the backrest can be moved.
Due to the high backrest and weight of these chairs it is virtually impossible to transport them in a car
• Wheelchairs with a tilt-in-space seat unit
With this type of design the seat and backrest angles are fixed so that they can be tilted backwards.
This feature is useful for people with particular seating needs that arise due to poor torso and head control. It is important to seek advice and get proper assessment from a wheelchair service, so that the user’s individual needs can be met appropriately.
• Stand-up wheelchairs
An occupant-controlled mechanism flattens the seat and backrest vertically, helping the user towards a standing position.
A new power chair from Ottobock, the C1000 SF with standing function (shown here), was developed following demand for a product that is more flexible when fitting individuals in the complex rehab segment. It helps people who do not have sufficient strength to move a wheelchair or bring themselves into an upright position, allowing the user to stand up even if they have very little strength and muscle tension of their own. Its biomechanics enable the user to achieve gentle standing that is physiologically and psychologically more assured.
It is said to be the first power chair in the world capable of achieving a fully extended standing posture. The chair can also be manoeuvred in the standing position – the speed is automatically reduced, for safety.
There are several advantages to a standing wheelchair: greater independence is achieved through being able to reach high objects, for example, and the psychological advantages of interacting with others at the same level can be considerable. At the same time, circulation and digestion may be improved by the ability to change position, and pressure points can be eased.
Negative factors – a long-term wheelchair user may find that their legs aren’t strong enough to support their body weight. Also, the stand-up mechanism makes the wheelchair heavier, and more difficult to push and to transport.
It is important to get good advice before trying this type of chair.