Leg is the anatomical structure of load-bearing and locomotive, usually with cylindrical shape. During exercise, the legs act as "stretchable support rods.". You can model the motion combination of all joints as a single linear element that changes the length and rotates around the omnidirectional hip joint.

As an anatomical animal structure, it is used for movement. The far end is usually modified to distribute the force (e.g., foot). Most animals have even legs.

As an integral part of furniture, it is used to save the economy of materials needed to support useful surfaces, desktops or chair seats.

The leg is a gross anatomical structure, which means it is large enough to be observed. The composition depends on the animal. In humans and other mammals, legs include bones, muscles, tendons, ligaments, blood vessels, nerves, and skin. In insects, legs include most of these things. In addition to insects, exoskeletons can replace the functions of bones and skin.

Sometimes the end of the leg or the foot is considered part of the leg. Sometimes it is considered separate. Similarly, you can think of a leg connected to the hip joint of the host or elsewhere as a separate or partial leg.