The Wheelchair - the ability to be mobile
The wheelchair market has changed dramatically in the last 20 years. Nowadays wheelchairs are not only conventional, they have where technology and material as well as design are concerned come much closer to the wishes and needs of people with disabilities.
A wheelchair ensures mobility for people who have a disability. This was the case for former US president Franklin D. Roosevelt, likewise for King Philip II of Spain in the second half of the 16 century, this also counts for the current German Home Secretary Wolfgang Schäuble and exactly so for all of our less famous handicapped fellow human beings. The requirements on mobility have also changed and so today in addition to conventional wheelchairs there are a variety of other models, from racing wheelchairs to beach wheelchairs available.
The offering is large but poorly organised, the drive configurations are varied. The correct choice of wheelchair increases mobility in school, in the workplace and in daily life and therefore contributes to increasing independence and social integration. When choosing a wheelchair attention needs to be paid to the fact that a wheelchair is a very personal aid. This acknowledgement must serve as the basis for all further steps. To ensure that the wheelchair can be properly implemented, it's important to understand exactly the type of disability as well as knowing all the functions of the wheelchair. Important factors here are the moving, standing and sitting functions. Just as important are the requirements concerning mobility and the planned place of use.
Diverse wheelchair types
Which primary systems are available? To begin; the folding wheelchair, whose biggest advantage is that it can be easily stored. This classic wheelchair is available from standard to modern active models. In principle all sizes of the folding wheelchair are adaptable. Seat width, depth, inclination and backrest height can be set to the required size and depending on the disability to the driver's ability. A rigid wheelchair can also be well stored away, even if the procedure is a bit different to that with a folding wheelchair. The rigid seat transfers the power better, which is a particular advantage for quadriplegics. The various folding mechanisms depend on the type axle being used.
Electric wheelchairs are available for users with profoundly little mobility and strength in the hands and arms. These can be classified according to their specific area of use in, indoor, outdoor and combination-electric wheelchairs; they are powered by a battery charged motor and are mostly controlled by means of a joystick.
On the beach with the wheelchair
There is a multiplicity of wheelchairs for the most diverse operational areas: Walker wheelchairs are designed to allow movement with the feet by means of a pattering like movement, shower wheelchairs are specially construed for taking a shower in an open shower unit, beach wheelchairs have very wide balloon tyres and are built with materials that are highly resistant to water, salt and sand. Racing wheelchairs on the other hand, are optimised for high speeds.
Efficiency of power utility is crucial
Wheelchairs are also differentiated in respect to the form of propulsion. There is a very wide range of varieties of manual wheelchairs. Ergonomics play an especially important role when energy input and energy loss are taken in to consideration. According to scientific investigations, the efficiency of an optimally adapted self propelled wheelchair amounts to a mere 9%. Over 90% of the energy used is lost. If the wheelchair is not optimally adapted to suit the user then the level of energy transfer is even less than 9%. Along with an optimal setup, determining factors like wheel friction, mode of steering, negative camber and the position of the body's midpoint to the drive axle play an important role in transfer of power to and agility of wheelchair.
Author: Patrick Gunti, August 2007. Translation: PmcC
Photo: © Sunrise Medical, Malsch at Heidelberg