The top of the talus fits into a socket that is formed by the lower end of the tibia (shin bone) and the fibula (smaller bone of lower leg). The talus then sits atop the calcaneus which is the heel bone. The talus acts like a hinge allowing the foot to move up (dorsiflexion) and down (plantarflexion).
Inside the joints, the bone is covered with a slick material called articular cartilage. This substance allows the bones in the joint to move smoothly one against the other. The cartilage is about one quarter to one inch thick in most joints that support the weight of the body such as the ankle, the hip, or the knee joints. It is soft enough to allow for shock absorption, yet tough enough to last a lifetime.
The ankle joint has to withstand 1.5 times your body weight when you walk and up to eight times your body weight when you run. It is the muscles, tendons, and ligaments that support the ankle joint by working together to propel the body forward. The foot itself is divided into three parts, the hindfoot, the midfoot, and the forefoot. The hindfoot contains two of seven tarsal bones which are the talus and the calcaneus; with the midfoot containing the other five tarsal bones, and for which all of the seven tarsals combined make up two parts of the entire foot.