Wheelchairs provide great support to disabled people. It is a chair with wheels. It is one of the most fascinating and effective inventions in the world. Let us see more facts and information about it.

HISTORY:

The first wheelchair was invented in the 5th century BCE by the Chinese. They used wheelbarrows to move around the people who are disabled. In the 12th century, the concept of wheelchairs started to begin in Europe. The first self-propelled wheelchair was developed in Germany in the year 1655. Wheelchairs became popularized in the medical field in the 18th century. The need for wheelchairs tremendously increased after World War II. The wooden wheelchairs remained the standard until 1930s. Herbert Everest together with his friend Harry Jennings started to redesign the model of wheelchairs to provide more comfort and also to improve mobility. They made the first foldable metallic wheelchair that got patented in 1937. They have founded the Everest & Jennings wheelchair company which was the world’s largest supplier of wheelchair from 1970s. They sold the company to Graham Field Health Products in the year 1996. Graham Field continues to market wheelchairs under Everest & Jennings name. Graham Field is one of the leading companies in the medical product manufacturing sector.

CATEGORY:

The wheelchairs are majorly categorized as:

  • Manually powered – These are the ones that use manpower. They are usually pushed by holding the hand rims on the wheels.
  • Externally powered – These types of wheelchairs use battery power and are also called electrically powered wheelchairs.
  • The other types include:
    • Pediatric wheelchairs
    • Positioning wheelchairs
    • Sports wheelchairs
    • All-terrain wheelchairs
    • Standing power wheelchairs
    • Depot wheelchairs
    • One-arm wheelchairs
    • Foot drive wheelchairs
    • Indoor wheelchairs
    • Ultralight wheelchairs
    • Stairclimbing wheelchairs

STRUCTURE AND COMPONENT DESIGN:

Several factors need to be considered before designing a wheelchair. The designer must be aware of the intended use of the person, the abilities of the person/user, resource availability, and also the availability of existing products.

Four critical performance factors needed to be considered are:

  1. Caster flutter
  2. Caster float
  3. Tracking
  4. Alignment

The materials used for the wheelchairs are:

  • Aluminium
  • Steel
  • Titanium
  • Composites such as Kevlar, carbon fiber, and polyester limestone.
Picture courtesy : Textbook of Rehabilitation

FRAMES

The frames of the wheelchair can be rigid or foldable. In general, the rigid frame is lighter and used more for sports activities and the folding frame is heavier and is convenient for storage since it occupies less space. The two common basic frame styles include:

  • Box frame – provides great strength and rigidity
  • Cantilever frame – The frame can act as suspension

TYRES

The tyre selection depends on the usage of the chair i.e., where it is being used. If it is designed for indoor usage the tyres are made with solid, hard polyurethane. Pneumatic(air-filled) tyres are used for outdoor purpose since it offers a smooth ride.

WHEELS

The size of the wheel varies according to the size and weight of the user. The types of available wheels are:

  • Solid Magnesium wheels – They are rigid and do not lose their shape. It does not require any adjustments.
  • Spoked wheels- These are lighter and are easily broken. It needs constant adjustments.

BRAKES

There is a separate brake for each wheel. A brake is applied to stop the chair, whenever the person is standing up or being transferred in or out of the chair.

CASTER

CASTERS

There are 2 casters present in front of the wheels. They can be small as well as large in diameter. Casters are pneumatic, semi-pneumatic or solid(polyurethane).

  • Pneumatic casters are good at shock absorption.
  • Semi-pneumatic casters are better on uneven terrain.
  • Solid casters are better on smooth terrain.

HANDRIMS

The hand rim depends on the user’s grip. The three basic types are

  1. Standard metal rims
  2. Friction rims
  3. Rims with projections

FOOTRESTS

Footrests are either fixed or moveable, it helps to maintain the feet in a neutral position. It also prevents deformities like the equinus (a condition in which the upward bending motion of the ankle joint is limited). Swing-away footrests are convenient but it increases the chair’s length.

ARMRESTS

Armrests are either fixed or adjustable. Removable armrests are more convenient. Books or trays and keyboards can be placed on these armrests.

BACKRESTS

Many wheelchairs are available with detachable backrests. The angle of the chair backs can be changed. High wheelchair backs provide greater trunk support and low wheelchair backs provide greater freedom for movement.

CUSHIONS

Cushions are used to provide great comfort to the user. The cushions may be air-filled, gel-filled, gel-inserted, or contour foam.

HEADREST

It is prescribed for people who have no head control or primitive neck reflexes. They are detachable.

CLOTHES GUARD

It prevents the clothes from getting entangled in the wheels of the wheelchair.

EXTRA ACCESSORIES

There is a huge array of accessories for wheelchairs. These include cup holders, cushions, seatbelts, storage bags, lights, and many more which can be included based on the requirements of the user.

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