Tibia

The tibia is the inner and thicker of the two long bones in the lower leg. It is also called the shin bone. Its upper end is expanded into "medial" and "lateral condyles," which have concave surfaces and unite with the condyles of the femur. The tibia is the supporting bone of the lower leg and runs parallel to the other, smaller bone (the fibula) to which it is attached by ligaments. The front of the tibia lies just below the skin and can easily be felt. The upper end joins the femur to form the knee joint, and the lower end forms part of the ankle joint. On the inside of the ankle, the tibia widens and sticks out to form a large bony prominence called the "medial malleolus." On the outside of the ankle is a protrusion called the "lateral malleolus," which is sometimes called the ankle bone, and is the most common area for ankle sprains.