What is the Calcaneus Bone?

The Heel Bone

If you suffer from foot pain, you may have heard the term “calcaneus bone.” But what is the calcaneus bone exactly? In plain English, it is the heel bone—the large, weight-bearing bone at the back of the foot. It forms the posterior aspect of the foot and is located just beneath the talus bone, helping form the ankle joint and subtalar joint. It's that hard bone closest to the ground, supporting body weight with every step.

If you've ever fractured your heel, you know the pain that comes with it, as well as the lengthy downtime. Calcaneus fractures, particularly intra-articular fractures involving the posterior facets, are known to cause chronic pain and mobility issues. The calcaneus articulates with both the talus and cuboid bones, forming complex articular surfaces that are essential for movement and stability.

Between your calcaneus bone and the ground is a vital layer of tissue called the plantar fascia, which attaches near the calcaneal tuberosity on the plantar surface. This connective tissue works in tandem with other structures like the long plantar ligament, plantar calcaneonavicular ligament, and plantar aponeurosis to support your arch and foot mechanics.

What is Plantar Fasciitis?

Fascia is a type of connective tissue found throughout the body. Have you ever bought chicken with the skin on and noticed a clear-ish, stretchy substance between the skin and meat? That’s fascia. On the bottom of your foot, the plantar fascia extends from the calcaneus bone to your toes.

When this band becomes inflamed, it causes heel pain—often described as a stabbing sensation—especially with the first steps in the morning. This condition is known as plantar fasciitis. It frequently stems from micro-tears near the calcaneal tubercle, located at the posterior surface of the calcaneus. The achilles tendon inserts on the posterior superior calcaneus, and its tightness can contribute to tension in the plantar fascia.

Other related structures that may become stressed include the flexor digitorum brevis, which originates from the medial process of the calcaneus, and the flexor hallucis longus, which courses near the medial aspect. These anatomical connections explain why plantar flexion issues or stress fractures in the foot and ankle can worsen symptoms.

Risk Factors for Foot Pain

Knowing how the calcaneus bone, heel bone, and plantar fascia work together can help prevent injuries. Common risk factors for calcaneal fractures, heel pain, and plantar fasciitis include:

• Distance running

• Obesity

• Long work hours on hard surfaces

• High arches or abnormal gait

• Injury or trauma to the foot and ankle

• Unsupportive shoes or shoe inserts

• Arthritis or connective tissue disorders

Chronic strain on the lateral and medial processes of the calcaneus, particularly in cases of overpronation or poor footwear, may cause pain relief efforts to fail without appropriate orthotics or physical therapy. Some calcaneal fractures can affect both the medial margin and lateral aspect, complicating healing and requiring medical intervention.

Why the Calcaneus Bone Matters

Understanding the surface of the calcaneus—including the medial surface, lateral surface, inferior surface, and dorsal aspect—can provide insight into common conditions and injuries. For example, the peroneal tubercle on the lateral wall of the calcaneus can become irritated due to overuse, especially in runners or athletes.

The calcaneus is unique for having three articular surfaces: the anterior facet, middle talar articular facet, and posterior facet. These help form the subtalar joint, which is crucial for inversion and eversion of the foot. Damage to the anterior and middle facets or involvement of the calcaneal sulcus and sinus tarsi may require internal fixation and extensive physical therapy after injury.

Tarsal fractures, including those involving the tarsal sinus, may also affect the posterior tibial artery or adjacent tarsal bones. Avulsion injuries may occur near the anterior surface or anterior tubercle due to sudden tension from the calcaneal tendon (another term for the achilles tendon).

Thoughtful Steps

As we age, maintaining foot health is crucial for mobility. Always choose athletic shoes that support the heel bone, reduce strain on the plantar fascia, and absorb impact at the posterior calcaneal surface. For severe or persistent pain, evaluation of the affected foot by a foot specialist may reveal avulsion fractures, sinus tarsi syndrome, or misalignment involving the middle facet.

If you're dealing with pain from the heel, posterior surface, or deeper issues involving other bones in the foot, don’t ignore it. Early diagnosis and targeted treatment can prevent long-term disability. And yes, wearing the right shoe size, using shock-absorbing heel support, and avoiding excessive stress are all simple ways to help.

Conclusion

When your calcaneus bone and plantar fascia are working in harmony, your feet can support you through years of walking, running, and standing. But when things go wrong—such as calcaneal fractures, tendon inflammation, or ligament strain—pain can ripple throughout your lower body, affecting your ankle joint, knee, and even your hip.

The good news? With the right knowledge and care—plus occasional support from physical therapy, proper insoles, and medical guidance—you can give your calcaneus the best chance at long-term health.

Sources: “Fractures of the Calcaneus (Heel Bone Fractures).” Fractures of the Calcaneus (Heel Bone Fractures) - Foot Health Facts, www.foothealthfacts.org/conditions/fractures-of-the-calcaneus-(heel-bone-fractures).
“Plantar Fasciitis.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 11 Dec. 2019, www.mayoclinic.org/diseases-conditions/plantar-fasciitis/symptoms-causes/syc-20354846.
Harvard Health Publishing. “7 Ways to Fix Foot Pain.” Harvard Health, www.health.harvard.edu/feet-and-foot-care/7-ways-to-fix-foot-pain.
Team, Family Health. “Chronic Heel Pain? 4 Simple Fixes for Your Plantar Fasciitis.” Health Essentials from Cleveland Clinic, Health Essentials from Cleveland Clinic, 9 Jan. 2020, health.clevelandclinic.org/chronic-heel-pain-4-simple-fixes-for-your-plantar-fasciitis/.