---

Manual wheelchair

Wheelchairs are used by people who have temporarily or permanently lost the ability to walk. In general, there are two types of wheelchairs, namely, those which are manually powered and those which have some form of power assist drive. Power wheelchairs are known and have been the subject of increasing development efforts to provide handicapped and disabled persons with independent mobility to assist them in leading more normal and active lives. While powered wheelchairs are highly advantageous in many situations, manually propelled or operated wheelchairs also can have many advantages. Motorized wheelchairs require no physical effort on the part of their users and can thus be used very easily by severely handicapped persons. However, as they are bulky, it is often difficult to use them in a confined space such as a dwelling. They are, furthermore, difficult to transport and expensive. Manual wheelchairs are typically preferred by many wheelchair users because they are light weight, compact, low cost, and easy to use. The choice of a wheelchair can depend on the nature of the user's handicap, on the activities that he or she practices and on the environment. A person having little activity outside the home may thus choose a wheelchair without a motor, whereas someone who wishes to travel over long distances may chose a motorized wheelchair. The manually powered wheel chairs are, by design, similar in their overall physical dimensions to allow for passage through doorways and share other similar features to allow for their collapse (folding) during transit in a car or other similar vehicle. Other similarities are also apparent in the seat and seat back construction and weight distribution, which permit the occupant to elevate the front wheels to navigate a curb or other obstruction. The manually driven wheelchairs, such wheelchairs typically have relatively small swivelling front wheels and large rubber rimmed rear wheels. Gripping rails may be provided on the rear wheels so that persons may propel themselves along by pulling down on the wheels or the gripping rims. Manually self-propelled wheelchairs have typically required the use of large wheels to provide the mechanical advantage necessary to convert occupant power to propulsion and to help move the chair over irregular surfaces. In a typical manually powered wheelchair, the seated chair occupant grasps large wheels on the chair and rotates the wheels in the desired direction of chair movement Circular hand grips are usually attached to the outside of the large wheels to facilitate the procedure. The most typical manual wheelchair brake is a manual "over center" locking device which is activated by a lever arm and, when forced into its locking position, presses a braking member against the surface of the wheelchair tire creating a frictional braking action.

---