A calcaneal ligament is one of multiple ligaments connecting the calcaneus, or heel bone, to the fibula bone of the shin, talus bone of the ankle, or tarsal bones of the foot. These include the calcaneofibular ligament, the interosseous talocalcaneal ligament, the calcaneocuboid ligament, the dorsal calcaneocuboid ligament, the calcaneonavicular ligament, and the plantar calcaneonavicular ligament. Each of these ligaments functions to hold the bones together while resisting forces on the foot that could potentially injure the joints between these bones.
Situated beneath the talus and behind the tarsus, the calcaneus is a many-faceted bone occupying most of the heel region of the foot. As it aligns with the leg bones and ankle joint directly above, this bone absorbs the body’s weight during gait movements and transfers it toward the front of the foot. It does so by forming a joint with the talus bone above it, which allows the foot to tilt from side to side on the ankle, and with two of the smaller tarsal bones in front of it, the cuboid and navicular bones.
These latter joints on the front end of the calcaneus, as well as the joint between the talus and navicular bones just above, permit a small amount of movement between the foot bones to help absorb shock on impact and transfer forces across the arch into the ball of the foot. To do so, they work in conjunction with the talocalcaneal joint by either allowing or prohibiting the foot bones to shift in relation to one another, depending on the position of the calcaneus against the talus during movement. It is the presence of each calcaneal ligament — that between the calcaneus and talus, calcaneus and cuboid, calcaneus and navicular, and even between the calcaneus and fibula above the ankle — that allows these bones to work as a unit during gait motions.
Constructed of densely bundled collagen, elastin, and other flexible fibers, the calcaneal ligament attaches the heel bone to the bones with which it articulates, or forms joints. On the bone’s top side, the interosseous talocalcaneal ligament joins the calcaneus to the underside of the talus bone overhead. From the lateral aspect of the bone, the same side as the fibula in the lower leg, the calcaneofibular ligament runs upward a short distance behind the interosseous ligament to attach to the outside of the fibula. These ligaments keep the calcaneus from detaching from the talus or tilting too far inward.
Just in front of the interosseous talocalcaneal ligament, another calcaneal ligament arises from the heel bone. A bifurcated or split ligament, its two sections unite the calcaneus with the cuboid and navicular bones in front. The calcaneonavicular ligament angles medially, or toward the same side of the foot as the first toe, crossing beneath the front end of the talus to reach the navicular bone. Splitting off toward the lateral side of the foot is the calcaneocuboid ligament, which joins the heel bone to the cuboid on that bone’s superior or top side.
Originating on the lateral side of the front end of the heel bone, another forward-oriented calcaneal ligament joins the calcaneus to the cuboid. Known as the dorsal calcaneocuboid ligament, it limits inversion, or tilting inward, of the foot in the transverse plane. Below that, stretching forward from the underside of the calcaneus, is the plantar calcaneonavicular ligament. This calcaneal ligament links the heel bone to the plantar side of the navicular bone under the arch of the foot, thus helping to uphold the arch.