Skeleton of lower limb

The skeleton of the lower limb or lower extremity consists of bones forming the pelvis and bones of the free lower extremity. The latter is subdivided into three parts - the thigh, leg and foot.

Pelvis

The pelvic skeleton or pelvic girdle is composed of two hip bones and the sacrum. Also, some authors consider that the coccyx is a part of the pelvis.

Each hip bone is formed by the fusion of three bones - pubis, ischium and ilium. A growing person has cartilages between all three bones that gradually ossify.

Free lower extremity

The upper part of the free lower extremity is known as the thigh, and it is formed by a single bone called the femur. The middle part of the free lower extremity is the leg (also known as the lower leg), and it consists of two parallel lying bones - tibia and fibula.

The final part of the free lower extremity is the foot, which is formed by three different groups of bones - tarsal bones, metatarsal bones and phalanges. Sometimes the foot contains some extra bones called the sesamoid bones.

Between the thigh and the lower leg lies the largest sesamoid bone in the human body - patella. It is a triangular-shaped bone lying over the anterior aspect of the knee joint.