The sharp or aching sensation on the inside of the ankle (medially) is a frequently reported issue among runners, often signaling that the body’s support structures are being overloaded. This area involves the bony prominence and the complex network of tendons, ligaments, and nerves that stabilize the foot’s arch. When subjected to the repetitive impact and forces of running, these structures can become strained, inflamed, or compressed. Understanding the specific cause of this medial ankle pain is the first step toward effective management and a successful return to running.
Common Causes of Medial Ankle Pain in Runners
The most frequent culprit behind inner ankle pain is Posterior Tibial Tendon Dysfunction (PTTD), often beginning as tendinitis. The posterior tibial tendon runs behind the inner ankle bone and attaches to bones on the underside of the foot, supporting the medial arch. Overuse from running can cause this tendon to become inflamed and painful, leading to swelling and tenderness along the inside of the ankle and arch. If inflammation progresses, the tendon may weaken and elongate, eventually leading to a progressive flattening of the foot’s arch.
Another distinct cause is Tarsal Tunnel Syndrome, which involves the compression or irritation of the posterior tibial nerve. This nerve travels through the tarsal tunnel, a narrow passageway located just behind the inner ankle bone. When compressed, the condition produces neurological symptoms, such as a burning sensation, tingling, numbness, or shooting pain that radiates into the arch and sole of the foot.
While less common, a Medial Stress Fracture is a more serious possibility, particularly in cases of insidious pain. This involves tiny cracks in the bone, such as the medial malleolus, caused by repetitive impact. Pain from a stress fracture is often localized to a specific, pinpoint tender spot on the bone and worsens during weight-bearing activities, sometimes persisting even at rest.
How Running Biomechanics Contribute to the Injury
The mechanical forces and movement patterns of a runner’s foot often place excessive stress on the medial ankle structures. Excessive pronation, or the over-rolling inward of the foot after landing, is the most influential biomechanical factor. While some pronation is natural for shock absorption, too much inward movement stretches the posterior tibial tendon and medial ligaments beyond their capacity. This constant overstretching and strain is a direct mechanism for PTTD and can contribute to nerve compression in the tarsal tunnel.
The type and condition of running footwear play a significant part in exacerbating poor mechanics. Worn-out shoes lose their ability to provide cushioning and stability, which increases the impact forces transmitted to the ankle. Similarly, running shoes that lack adequate medial support for a foot prone to overpronation fail to control the inward roll, increasing the workload on the stabilizing tendons.
Training errors, particularly those related to volume and intensity, are the primary triggers for these overuse injuries. A rapid increase in weekly mileage, intensity, or the sudden incorporation of speed work or hill running can overload the tendon and bone tissue. The tissues are not given sufficient time to adapt to the higher mechanical load, which initiates the cycle of inflammation and breakdown.
Immediate Steps for Pain Relief and Recovery
Upon experiencing inner ankle pain during a run, the immediate priority is to reduce the mechanical load and control inflammation. The initial management protocol follows the principles of RICE: Rest, Ice, Compression, and Elevation. Rest involves immediately ceasing running and avoiding any activities that cause pain. Applying ice to the tender area for 15 to 20 minutes several times a day during the first 48 hours helps reduce swelling and pain. Compression with an elastic bandage helps limit swelling, while elevating the foot above heart level assists in draining excess fluid.
During this initial phase, switching to non-impact activities, such as swimming or cycling, allows the irritated structures to rest while maintaining cardiovascular fitness. Temporary modifications like using supportive shoe inserts or wearing a brace can stabilize the foot and reduce strain on the medial structures during daily walking. Seek immediate attention if you experience severe pain, an inability to bear weight, significant swelling that does not improve after 48 hours, or any sensation of numbness or tingling. Pain that persists or worsens despite several days of rest also warrants a consultation for an accurate diagnosis.