Pain on the inside of the ankle while running, known as medial ankle pain, is a common complaint among distance runners. This discomfort often presents near the arch and the medial malleolus, the bony prominence on the inside of the ankle. Running places continuous stress on the complex structures of the lower leg. Pain in this region is typically an overuse injury, meaning a tendon, nerve, or bone is being overloaded beyond its capacity to recover.
Identifying the Primary Causes of Medial Ankle Pain
The most frequent diagnosis for medial ankle pain is Posterior Tibial Tendon Dysfunction (PTTD), often starting as tendonitis. The posterior tibial tendon runs along the inside of the ankle, supporting the arch and controlling the foot’s inward roll during the running stride. Overuse causes inflammation (tendonitis) or, with prolonged stress, degeneration (tendinosis). Pain is usually felt behind the medial malleolus and may radiate into the arch, often worsening as a run progresses.
Another group of issues involves stress-related injuries to the bone. Medial Tibial Stress Syndrome (MTSS), commonly known as shin splints, involves irritation of the tissue surrounding the tibia, with pain sometimes radiating into the ankle area. More serious are stress fractures, tiny cracks often affecting the navicular bone or the distal tibia. These injuries result from microtrauma accumulation when bone breakdown outpaces rebuilding, causing sharp, localized pain that is tender to the touch.
A less common, but important, cause is Tarsal Tunnel Syndrome (TTS), which is a nerve entrapment condition analogous to carpal tunnel syndrome in the wrist. The tarsal tunnel is a narrow passageway on the inside of the ankle containing the posterior tibial nerve, blood vessels, and tendons. Compression of this nerve, often due to swelling from overuse or fallen arches, causes symptoms that are distinct from tendon pain. TTS is characterized by shooting or burning pain, tingling, or numbness, which is typically felt on the sole of the foot or the inside of the ankle.
Biomechanical Stressors Related to Running Form
The primary mechanical factor linking running to medial ankle pain is excessive foot motion, particularly overpronation. Pronation is the natural inward roll of the foot after landing, which helps absorb shock, but overpronation is an exaggerated or prolonged inward roll. This excessive motion places a high tensile load on the posterior tibial tendon as it works to stabilize the arch and prevent the foot from collapsing, leading directly to the inflammation and damage characteristic of PTTD.
This excessive strain can originate higher up the kinetic chain, particularly from weakness in the hip and gluteal muscles. The hip abductors and gluteal muscles are responsible for stabilizing the pelvis and femur during the single-leg stance phase of running. If these muscles are weak, the knee may collapse inward (dynamic valgus), which subsequently forces the foot into a position of increased overpronation. This chain reaction amplifies the stress on the lower leg structures, including the medial ankle tendons.
Training errors are also significant contributors to medial ankle overload. Structures like the posterior tibial tendon are cumulative-load tissues, meaning they adapt slowly to increasing stress. A sudden increase in weekly mileage, intensity, or excessive hill work can quickly exceed the tissue’s adaptive capacity, initiating micro-damage and symptomatic pain.
Immediate Management and Medical Triage
When medial ankle pain is first felt, the immediate priority is to reduce the load on the irritated structures to prevent further damage. The initial management protocol involves the principles of Rest, Ice, Compression, and Elevation. Discontinuing running and applying ice to the painful area for 10 to 20 minutes several times a day can help reduce acute inflammation and pain.
During this acute phase, engaging in low-impact cross-training activities, such as cycling or swimming, allows a runner to maintain cardiovascular fitness without placing repetitive strain on the injured ankle structures. However, any activity that reproduces the pain should be avoided completely. The goal of this initial rest period is to allow the tissue to begin the healing process.
When to Seek Medical Evaluation
A runner should seek professional medical evaluation if they experience specific red flags. These include sudden, severe pain, an inability to bear weight on the affected foot, or the presence of visible swelling or deformity. If the pain persists or fails to improve within one to two weeks despite consistent rest and ice application, a medical assessment is necessary to rule out a stress fracture or advanced tendon dysfunction.
Long-Term Rehabilitation and Recurrence Prevention
Long-term recovery focuses on strengthening injured structures and correcting underlying biomechanical faults. A structured rehabilitation program involves specific exercises to build the load capacity of the posterior tibialis muscle. This includes resistance band exercises for inversion and progressive heel raises, starting on two legs and advancing to single-leg raises, focusing on controlling the lowering phase.
Addressing the foot’s mechanics is a primary part of recurrence prevention. Orthotic devices, whether custom-made or over-the-counter arch supports, provide mechanical support to the arch and reduce strain on the posterior tibial tendon during the stance phase. Choosing running shoes that offer greater stability or motion control can also help limit overpronation.
Rehabilitation also requires strengthening the upstream muscles, particularly the hip abductors and gluteals, to improve the dynamic stability of the entire leg. This helps control the inward collapse of the knee and foot during running, reducing the stress transferred to the medial ankle. The final phase of recovery involves a slow, structured return to running, gradually increasing mileage and intensity to ensure the strengthened tissues can tolerate the repetitive impact without a relapse.