Inner Ankle Pain When Running: Posterior Tibial Tendonitis
Why does the inside of your ankle hurt when running?
Pain along the inside of your ankle, roughly between the ankle bone and the arch, is most often posterior tibial tendonitis (also called tibialis posterior tendinopathy) — irritation of the tendon that runs behind your inner ankle bone and supports your arch. It usually develops gradually from repetitive loading rather than a single injury. Running injuries overall are estimated to be roughly 70-80% overuse-related rather than caused by one traumatic event, and this tendon is a frequent site of that overuse because it works on every single stride to control how much your foot rolls inward.
What does the posterior tibial tendon actually do?
The tibialis posterior muscle sits deep in your calf, and its tendon wraps behind the bony bump on the inside of your ankle (the medial malleolus) before attaching along the bottom of your midfoot and arch. Its main job during running is to control pronation — the natural inward roll and flattening of the foot after it lands — and to help lift the arch back up as you push off. Every stride asks this tendon to decelerate that inward roll while generating force to support your body weight, which makes it vulnerable when weekly mileage or intensity increases faster than the tendon can adapt.
When the tendon is chronically overloaded, it can become painful, thickened, and less able to support the arch. Over months to years, unmanaged posterior tibial tendon dysfunction is considered a leading cause of adult-acquired flatfoot, because a failing tendon gradually allows the arch to collapse. That's a long-term consequence, not something that happens overnight — most runners feel the ache long before any visible change in arch height.
Pain here is sometimes confused with pain from other arch structures. See why the arch of your foot hurts when running for help telling posterior tibial pain apart from plantar fascia or other arch pain.
How are overpronation and hip drop connected to inner ankle pain?
Overpronation — when the foot rolls inward more, or for longer, than it needs to during stance — puts extra demand on the posterior tibial tendon, since that tendon is the main brake on inward roll. Runners who overpronate often also show a hip drop on the same side: the pelvis dips when weight is on the affected leg, usually because the hip abductors (glute medius in particular) aren't stabilizing the pelvis well. Weaker or fatiguing hip muscles change how load travels down the leg, so the ankle and tendon end up absorbing more stress stride after stride.
This is an association worth screening, not a strict cause-and-effect rule. Research linking foot-strike and pronation patterns to injury is mixed — plenty of runners overpronate without ever developing tendon pain, and some with textbook mechanics develop it anyway. Overpronation and hip drop are reasonable things to check if you have inner ankle pain, but they aren't a diagnosis by themselves.
How can you test your posterior tibial tendon at home?
A simple, low-risk screening tool physios commonly use is the single-leg calf raise test. Stand on the affected leg only, holding a wall or chair for balance if needed, and rise onto the ball of that foot as high as you comfortably can, then lower slowly. Compare it to the uninjured side.
Things worth noting — as clues, not a self-diagnosis:
- Pain directly behind the inner ankle bone during the raise
- Noticeably less height, or a wobblier arch, on the affected side
- Difficulty completing about 10 clean single-leg raises when the other side manages it easily
- The arch failing to lift and "cup" normally at the top of the raise
This test can point toward the posterior tibial tendon as a suspect, but it doesn't rule other structures in or out. Treat it as a screening cue to bring to a physiotherapist or sports medicine clinician. If the discomfort sits more in the belly of the calf than right at the ankle, it's also worth comparing against a calf strain versus general calf tightness before assuming the tendon is the source.
How is posterior tibial tendonitis treated?
Tendon pain generally responds to a progressive loading program rather than pure rest. Rest can reduce pain short-term, but tendons need graded load to remodel and tolerate running again — under-loading for too long often just delays the same pain when you resume. Most tendinopathy rehab protocols described in the sports-medicine literature run 12 weeks or longer, because tendon tissue adapts more slowly than muscle.
A typical progression looks something like this — general guidance, not an individualized prescription:
| Phase | Approx. timeframe | Focus |
|---|---|---|
| Settle | Weeks 1-2 | Reduce aggravating activity, isometric calf/tendon holds, address obvious pain triggers |
| Build capacity | Weeks 3-6 | Progressive calf-raise loading (straight and bent knee), single-leg balance, hip-abductor strengthening |
| Add energy storage | Weeks 7-10 | Heavier and faster loading — resisted heel raises, hopping progressions — as pain allows |
| Return to running | Weeks 10-12+ | Gradual run-walk reintroduction, then mileage build once single-leg calf raises are pain-free and roughly symmetrical |
Cutting corners on the final phase is a common reason tendon pain comes back. Pairing structured rehab with a sensible mileage build — many coaches use roughly a 10% weekly mileage increase as a starting guideline, adjusted to how the tendon is responding — reduces the chance of re-aggravating it. If you're unsure how long to step back from running in the first place, general guidance on resting a running injury walks through how clinicians typically approach that decision.
Alongside loading, addressing the hip-drop and overpronation pattern mentioned earlier — through glute medius strengthening, and sometimes a temporary supportive insole — is common practice, though its effect is mostly about reducing ongoing strain rather than healing the tendon directly.
A phone-based gait check, like the one StrideIQ provides from a short side-view running video, can flag an asymmetric hip drop or a cadence that's noticeably low for your pace — useful context to bring to a physio appointment. It's a reasonable way to get a quick, objective look at your stride between clinical visits, not a substitute for a hands-on assessment of the tendon itself.
What can form analysis NOT tell you?
Video-based form analysis, phone or otherwise, has real limits here. A single phone video can measure cadence (steps per minute) fairly reliably, and that's the most trustworthy number it can give you. Ground contact time, vertical oscillation, and precise ankle or hip joint angles can only be estimated from a phone clip, because accurately measuring those needs high-speed or multi-camera capture — a phone video gives a rough visual impression, not a lab-grade figure.
More importantly, no video analysis can tell you whether inner ankle pain is tendonitis, a stress reaction, tarsal tunnel irritation, or something else — that distinction needs a hands-on exam and sometimes imaging. If pain persists beyond a couple of weeks, worsens, causes swelling that doesn't settle, or changes the visible shape of your arch, see a physiotherapist or sports medicine doctor rather than training through it or self-treating from an app score. Form feedback and loading programs are tools to use alongside professional care, not instead of it.
Frequently Asked Questions
Is posterior tibial tendonitis the same as shin splints?
No. Shin splints (medial tibial stress syndrome) cause pain along the shin bone itself, while posterior tibial tendonitis causes pain specifically behind and below the inner ankle bone, where the tendon runs. They can coexist, and both are overuse injuries, but they involve different tissues and often different rehab emphasis.
Can flat feet cause posterior tibial tendon pain even if I've never had ankle pain before?
Yes, flatter or more mobile arches place more day-to-day demand on the posterior tibial tendon, which can make it more prone to overuse pain when mileage or intensity increases. That said, plenty of runners with flat feet never develop tendon pain, so foot shape alone isn't a reliable predictor — it's one factor among training load, strength, and recovery.
How long does posterior tibial tendonitis take to heal?
Tendon issues typically take longer than muscle strains to settle. Many structured rehab programs for tendinopathy run 12 weeks or more before a full return to prior running volume, with the first couple of weeks focused on calming symptoms and later weeks on progressive strength and return-to-run loading. Individual timelines vary and should be guided by a clinician.
Can I keep running with mild inner ankle pain?
Some clinicians allow light running if pain stays low (often described as mild and not worsening during or after the run) and settles within a day. If pain is sharp, increasing, or lingers beyond 24 hours, it's a signal to scale back and get it assessed rather than pushing through — this isn't a rule you should self-apply without guidance.
Do supportive shoes or orthotics fix posterior tibial tendon pain?
Supportive footwear or a temporary insole can reduce strain on the tendon while it recovers, and some people find them helpful long-term for symptom management. They aren't a cure on their own — most improvement comes from progressive loading and addressing hip and calf strength, with footwear as a supporting piece rather than the main treatment.
Sources
- American Academy of Orthopaedic Surgeons — "Adult-Acquired Flatfoot"
- British Journal of Sports Medicine — "Epidemiology of running-related musculoskeletal injuries"
- Journal of Orthopaedic & Sports Physical Therapy — "Clinical practice guidelines for tendinopathy management and loading progression"
- American Physical Therapy Association — "Posterior Tibial Tendon Dysfunction: Patient Guide"