A knee scooter or knee walker is a two, three or four-wheeled alternative to crutches or a traditional walker as an ambulation aid. It is known by many other names, such as a knee walker, knee cruiser, knee caddy, orthopaedic scooter, or leg walker.
Over the years it has taken on many forms, from small-wheeled devices suitable for indoor use to larger sturdier units capable of use outside on grass or paved surfaces. Today’s version is usually a lightweight, foldable design that, with the knee flexed, supports the shin of the unusable limb. The opposite foot makes contact with the floor or ground, providing propulsion.
The objective of the scooter is to create a safe, comfortable, and easy-to-maneuver alternative to the traditional crutch. Prior to its introduction, those experiencing foot surgery, bunionectomies, gout, below the knee amputations, diabetic ulcers and wounds, as well as foot sprains, or fractures had no choice but to limit activity during rehabilitation. Their only options were crutches, a traditional walker, a wheelchair or bed rest.
The scooter does have limitations that may make it unsuitable for some patients, such as those with leg injuries above or near the knee. It cannot negotiate stairs, and is significantly heavier and more difficult to load into a vehicle than crutches.
Attendant-propelled chairs (or transport wheelchairs) are designed to be propelled by an attendant using the handles, and thus the back wheels are rimless and often smaller. These chairs are often used as 'transfer chairs' to move a patient when a better alternative is unavailable, possibly within a hospital, as a temporary option, or in areas where a user's standard chair is unavailable. These chairs are commonly seen in airports, theme parks and attractions. Special airplane transfer chairs are available on most airlines, designed to fit narrow airplane aisles and transfer wheelchair-using passengers to and from their seats on the plane.