Hindfoot: Anatomy, Location, and Function

The hindfoot, sometimes also referred to as the rearfoot, is the posterior region of the human foot as differentiated from the midfoot and the forefoot. The hindfoot area includes the talus and calcaneus bones; the subtalar and talocrural (ankle) joints; and the muscles, tendons, and ligaments in the heel area. Differences in the way the hindfoot strikes the ground, such as overpronation and supination, can contribute to pain in the feet, knees, legs, hips, or back. Irregularities in the fascia, or connective tissue, of the hindfoot also contribute to the condition known as plantar fasciitis.

The hindfoot contains only two bones, which together make up the largest bony structures of the foot: the talus, otherwise known as the ankle bone; and the calcaneus, or the heel bone.

The ankle joint, also known as the talocrural joint, is located between the talus and the two bones of the lower leg: the tibia (shin bone) and fibula (small bone supporting the tibia). It operates is a hinge joint, allowing the foot to tilt upward (dorsiflexion), and downward (plantarflexion).

The subtalar joint is located between the calcaneus and the talus bones and allows the foot to roll side to side, thereby turning the sole inward or outward (inversion and eversion). This action is particularly necessary when navigating rough terrain.

The foot contains numerous intrinsic muscles, or those originating in the foot, that are responsible for toe movements, arch support, and maintaining upright posture. Of these, the abductor hallucis, abductor digiti minimi, and the flexor digitorum brevis are found—at least in part—in the hindfoot area. Ligaments and tendons in the hindfoot connect the rear parts of the foot to other parts of the foot or leg (as is the case with the Achilles tendon), aid movement, and contribute to balance and stability.

Because of their location in the heel area, the various components of the hindfoot affect—and are affected by—the rest of the foot and the lower leg. Misalignments in the way the hindfoot strikes the ground can contribute to pain further up the leg, as well as in the hips and back.

Numerous anatomical variations, such as the presence of accessory ossicles, or small bones, can be observed in the rearfoot via radiograph. Often, these variations are asymptomatic, though it's also possible for them to contribute to pathology or pain.

The rearfoot's structure is essential to the functionality of the entire foot. Additionally, the health and biomechanics of the rearfoot help determine gait and can contribute to pain in the feet and many of the joints above.

For many people, the rearfoot strikes the ground first when walking or running, though there is disagreement about whether rearfoot strikes—as opposed to forefoot and midfoot strikes—are the optimal pattern of movement. Regardless of your strike pattern, the rearfoot area works along with the rest of the foot to allow movement, balance, and stability for a variety of everyday actions.

Overpronation refers to an inward roll of the foot often associated with flat feet, and supination (or underpronation) refers to the opposite, or outward roll of the foot. Both overpronation and supination can negatively affect the bones, joints, tendons, and ligaments in the rearfoot itself as well as in other parts of the foot and the leg.

Overpronation and supination are common congenital abnormalities that become apparent as a child develops and can often be detected by observing a person's gait. These differences cause the foot to invert or evert—or "tilt" inward or outward at the ankle—when the rearfoot is weight-bearing. While they are not normally serious, overpronation and supination can cause pain in the feet, legs, knees, hips or back. 

Plantar fasciitis is a common condition involving the fascia, or connective tissue, spanning from the rearfoot to the forefoot. Its most common symptom is a burning sensation on the heel area when walking, particularly first thing in the morning or after prolonged sitting. While it was previously thought that plantar fasciitis resulted from inflammation, now plantar fasciitis is more commonly thought of as a degenerative process. Heel spurs are small, bony growths on the heel that may result from chronic plantar fasciitis.

In addition to problems stemming from overpronation, supination, and plantar fasciitis, other conditions affecting the hindfoot may include fractures, bruises, bursitis, arthritis, and entrapped nerves.

Some sources of pain in the hindfoot area can be remedied simply with the use of well-fitting shoes that provide cushion and stability, and with simple stretching and strengthening of the foot, ankle, and calf.

To address plantar fasciitis, a combination of rest, stretching, strengthening, icing, sports taping, and orthotics can be helpful. If home care fails to alleviate the pain, consult with your doctor about next steps, which could include physical therapy, ultrasound treatment, or surgery. It may be possible to correct flat feet caused by overpronation through stretching, orthotics, or surgery.