leg - The human leg

A term commonly used to refer to the whole of the lower limb, primarily used for support and movement; more precisely, in anatomy, the region between the knee and ankle joints, distinguished from the thigh (between the hip and knee joints) and the foot (beyond the ankle joint). It articulates with the trunk via the pelvic girdle (the hip bones and sacrum). The bones are the femur in the thigh, the tibia and fibula in the leg, and the tarsals, metatarsals, and phalanges in the foot. The muscles on the front of the thigh and leg cause flexion at the hip, and extension at the knee and ankle joints and of the toes; those on the back of the thigh and leg cause opposite movements. The muscles within the foot also move the toes.

In general, a leg is the part of an animal's body that support the rest of the body above the ground and is used for locomotion. In higher land animals, such as the tetrapod vertebrates, anatomists usually use the term 'leg' to refer to the portion of the limb distal to the hip joint (hind limb) or shoulder joint (fore limb).

In bipedal vertebrate animals, the lower limb is usually referred to as the 'leg' and the upper limb as the 'arm'.

The human leg

The bones of the human leg are:

the femur (or thighbone), which attaches to the pelvis the patella (kneecap) the tibia (shinbone) the fibula (calf bone)

The front edge of the tibia is not covered by a thick layer of muscle or fat: this is why being kicked in the shins is so painful.