A wheelchair is a device that gives mobility for whom walking is difficult or impossible due to physical disability (degenerative disease, accidents). The operator can move by turning one or both of two wheels attached or can have a motor to move so operator only has control it - change directions, stop or go. Wheel chairs can also be used by a third party to transport people who are unable to operate the chair themselves (e.g. stroke victim).
Today, they can be highly customised or even custom-built for the individual user's needs to make them as comfortable and functional as possible.
• Manual wheelchairs - require human power to move them. Some chairs are also configured to allow the occupant to propel using one or both feet instead of hands.
• Attendant-propelled chairs - moved by an attendant using the handles, and thus the back wheels are rimless and often smaller.
• Electric-powered wheelchairs - generally prescribed for persons who have difficulty using a manual chair
• Standing wheelchairs - one that supports the user in a nearly standing position using a hydraulic pump or electric-powered assist.
• Power-assisted wheelchair - uses the frame and seating of a typical manual chair while replacing the standard rear wheels with wheels that have small battery-powered motors in the hubs.
• Sporting wheelcahirs - disabled athletes use for disabled sports that require speed and agility.
Using gyroscopic technology and other advances, chairs can now balance and run on only two of its four wheels on some surfaces, thus raising the user to a height comparable to a standing person.
Stair-climbing ability with 4WD features and motorised assists for hand-powered chairs are becoming available thus doing way with the need of special stairs and ramps in homes.