Posterior ankle pain refers to discomfort experienced at the back of the ankle joint. While often a minor issue that resolves with rest, pain in this area can also signal more significant underlying conditions.
Common Tendon-Related Pain
One of the most frequent sources of pain at the back of the ankle involves the Achilles tendon, which connects the calf muscles to the heel bone. Achilles tendinopathy, a condition characterized by changes within the tendon structure, commonly results from repetitive stress or overuse. Symptoms typically include a dull ache or stiffness along the back of the lower leg, especially noticeable in the morning or after periods of inactivity. This discomfort often lessens with light activity but can significantly worsen with increased exertion or prolonged standing.
Contributing factors to Achilles tendinopathy often include sudden increases in physical activity, improper footwear, or tightness in the calf muscles, which place additional strain on the tendon. These stresses can lead to microscopic tears and disorganized healing within the tendon fibers, resulting in persistent pain, localized thickening, and reduced function.
A more severe and acute injury is an Achilles tendon rupture, a complete or partial tear of the tendon fibers. This debilitating injury often occurs during explosive movements like jumping or sprinting, accompanied by a distinct “popping” sound, immediate sharp pain, and a sensation of being kicked. A noticeable gap or indentation may appear above the heel, and the ability to push off or stand on toes becomes significantly impaired. This type of injury requires prompt medical evaluation and often surgical intervention.
Bone and Bursa Irritation
Beyond tendon issues, pain at the back of the ankle can also stem from irritation of bone or bursae, small fluid-filled sacs. Retrocalcaneal bursitis, an inflammation of the bursa between the Achilles tendon and heel bone, is a common cause. This results in pain and swelling directly in front of the Achilles tendon insertion point. Discomfort often worsens with activities that compress the bursa, such as wearing tight or rigid shoes, or with ankle movement like pushing off the foot. Localized swelling can sometimes be visible as a soft, tender lump at the back of the heel.
Another structural issue is Haglund’s deformity, or “pump bump,” a bony enlargement on the upper heel bone near the Achilles tendon. This prominence can irritate the Achilles tendon or retrocalcaneal bursa, leading to chronic inflammation and pain. The deformity often presents as a noticeable bump on the back of the heel, which can become red and tender due to shoe irritation. Pain typically worsens with activity or when wearing footwear with rigid backs, as these put direct pressure on the bony prominence. This irritation can also contribute to Achilles tendinopathy over time.
Nerve Compression
Nerve irritation can also be a source of discomfort at the back of the ankle. Tarsal Tunnel Syndrome occurs when the tibial nerve, running along the inside of the ankle, becomes compressed within the tarsal tunnel. This narrow space, formed by bone and a strong fibrous band, makes the nerve vulnerable to entrapment from factors like swelling or abnormal foot mechanics. Compression can lead to pain, numbness, tingling, or a burning sensation, often felt at the back of the ankle or radiating into the arch of the foot or toes. Symptoms may worsen with prolonged standing, ankle movements, or certain foot positions.
Other Possible Explanations
While less common, other factors can contribute to pain experienced at the back of the ankle. Stress fractures, tiny cracks in bones, can develop in the heel bone (calcaneus) or lower shin bone (tibia) from repetitive impact or overuse. Pain is typically localized, sharp, and intensifies with activity, gradually easing with rest. Early recognition is important to prevent progression.
Pain felt in the ankle may sometimes be referred from issues higher up the leg or lower back. Problems with nerves in the lumbar spine, for example, can cause pain that travels down the leg and is perceived in the ankle, creating diagnostic challenges.
Systemic inflammatory conditions can also affect the ankle joint. Autoimmune diseases like rheumatoid arthritis or metabolic conditions such as gout can cause significant inflammation, swelling, and pain in various joints, including the ankle. These conditions typically present with additional body-wide symptoms, requiring broader medical assessment.
When to Consult a Professional
While some posterior ankle pain may resolve with rest and home care, certain signs indicate the need for professional medical evaluation. Seek immediate attention if you experience severe pain preventing weight-bearing, or a sudden onset of pain with a distinct popping sound, which could indicate an Achilles tendon rupture. Noticeable deformity, significant swelling, or signs of infection like redness, warmth, or fever also warrant prompt medical assessment.
Any numbness, tingling, or weakness in the foot or toes should also be evaluated by a healthcare professional, as these symptoms can suggest nerve involvement. If your ankle pain persists or worsens despite several days of rest, ice, and elevation, consult a doctor. Persistent pain suggests an underlying issue requiring specific treatment beyond self-care.
A healthcare professional can accurately diagnose the cause of your ankle pain through a thorough physical examination and, if necessary, advanced imaging studies like X-rays, ultrasound, or MRI. A precise diagnosis is important for developing an effective treatment plan, preventing chronic issues, and promoting better long-term outcomes.