Typically, a wheelchair consists of four wheels: two large wheels in the rear, which are used for propelling the wheelchair,
buy electric wheelchairs and two small wheels in the front, which swivel and are called casters. The large wheels support the majority of the individual’s weight and provide the primary means of propulsion. The casters facilitate maneuverability. Traditionally, wheelchairs are divided into two categories: manual and electric-powered. Those categories are defined by the mechanism used to propel the wheelchair. A manual wheelchair is propelled by human power, and an electric-powered wheelchair is propelled by an electrically based power source (typically a battery and electrical motor).
