The ankle bones include the calcaneus, cuboid, external cuneiform, internal cuneiform, middle cuneiform, navicular, and talus. The talus sits at the top, under the fibula and tibia (the bones of the lower leg). Ligaments and tendons (types of fibrous connective tissue) connect the leg bones with the ankle bones, thus preventing slippage. They also offer stability during movement. Tendons protect the ligaments. When a person is standing, the ligament is slack. The calcaneofibular ligament's responsibility is to control inversion. Inversion involves turning the foot on its side, so the bottom of the foot faces the opposite foot.
The calcaneofibular ligament connects the talus and calcaneus (heel) bones of the foot. The ligament is two centimeters long, five millimeters wide, and three millimeters thick.
Damage to this ligament occurs when the foot twists too much while the toes point upwards towards the shin. Doctors diagnose damage with a talar tilt test. During a talar tilt test, the patient sits on a bench with the foot flat or slightly angled. The doctor holds the leg above the ankle and manipulates the foot to create inversion. If there is pain, the doctor knows the ligament connecting the talus and calcaneus is the cause.