WHY DOES THE INSIDE OF MY ANKLE HURT AND MY FOOT ARCH LOOK FLATTER? A PHYSICAL THERAPIST ANSWERS

Published October 26, 2026

Patient Question

“My ankle hurts on the inside when I walk, and I’ve noticed that the arch of my foot seems to be getting lower. Is this normal aging, or could something be wrong with a tendon?”

The Short Answer

Pain along the inside of the ankle, especially when combined with a gradually flattening arch, may be associated with irritation or dysfunction of the posterior tibial tendon. This tendon helps support the arch and control the foot during walking. One possible diagnosis is posterior tibial tendon dysfunction (PTTD), which may occur as part of progressive collapsing foot deformity (PCFD). Other conditions can cause similar symptoms, so a clinical examination is important.

What Does the Posterior Tibial Tendon Do?

The posterior tibialis muscle is located deep in the lower leg. Its tendon travels behind the inner ankle and attaches to structures along the inside of the foot. It helps support the medial longitudinal arch, control foot motion, and assist with push-off during walking. A naturally low arch does not automatically mean someone has tendon disease.

What Are the Common Symptoms?

Symptoms may include pain or swelling behind the inner ankle bone, discomfort after prolonged walking or standing, difficulty with a single-leg heel raise, a gradually lower arch, and changes in walking mechanics. Some people with more advanced changes also develop pain along the outside of the ankle. A progressively changing foot shape deserves medical assessment.

Why Might This Happen?

Posterior tibial tendon problems can involve a combination of tendon overload, reduced muscle capacity, altered foot mechanics, and age-related changes. Previous injury and some inflammatory or systemic conditions may contribute. The problem is not always caused by a single shoe, exercise, or activity.

Can Physical Therapy Help?

Physical therapy may help improve pain, muscle performance, balance, walking tolerance, and daily function, particularly in appropriate early-stage cases. Rehabilitation may include progressive strengthening of the posterior tibialis and calf muscles, foot-intrinsic muscle training, balance activities, and graded return to walking. Footwear changes or orthoses may also be appropriate. Patients with significant deformity may need coordinated care with a foot-and-ankle specialist. At Nova Physical Therapy, treatment planning is guided by individual examination findings and goals.

Which Exercises Might Be Used?

Examples include seated resisted ankle inversion, supported bilateral heel raises, short-foot exercises, supported single-leg balance, and gradual walking progression. These are examples, not a universal prescription. Exercise selection and intensity should reflect pain, strength, foot alignment, and functional tolerance. A marked or sustained increase in pain, swelling, or walking difficulty warrants reassessment.

What Does Research Say?

A systematic review of randomized trials in BMJ Open Sport & Exercise Medicine found that exercise-based approaches may improve certain outcomes in posterior tibial tendon dysfunction, although the trials were small and evidence was limited. This supports individualized progressive rehabilitation rather than claiming one protocol works for everyone. See the systematic review and AAOS patient information.

What Happens During a Physical Therapy Evaluation?

A physical therapist may assess ankle and foot motion, tenderness, muscle performance, balance, gait, and tasks such as heel raises. The evaluation may also consider hip strength, footwear, activity changes, and whether the foot remains flexible. Findings suggesting substantial deformity, suspected rupture, or another medical condition may require referral.

When Should You Seek Medical Attention?

Arrange a medical evaluation if your arch is visibly changing, pain is persistent or worsening, or walking and heel raises are becoming increasingly difficult. Seek urgent assessment for an acute injury with inability to bear weight, severe swelling or deformity, new loss of sensation or circulation, or a red, hot, swollen foot with fever. Sudden warmth and swelling in a person with diabetes or neuropathy also warrants prompt medical assessment.

Why Patients Choose Nova Physical Therapy — We Care

At Nova Physical Therapy in North Hollywood, our approach emphasizes individualized movement assessment, patient education, and progressive rehabilitation. We consider how the foot, calf, knee, and hip work together during daily activities. Explore our physical therapy services.

Frequently Asked Questions

1. Can posterior tibial tendon dysfunction cause flat feet?

It can contribute to a progressive reduction in arch height, but not every flat foot is caused by tendon dysfunction.

2. Does inner ankle pain always mean PTTD?

No. Ligament injuries, arthritis, nerve irritation, stress injuries, and other conditions can cause similar symptoms.

3. Can physical therapy restore my arch?

Physical therapy may improve symptoms and function, but cannot be assumed to reverse structural deformity.

4. Should I stop walking?

Not necessarily. Activity modification may be appropriate; the right amount depends on symptoms and clinical findings.

5. Are heel raises helpful?

They can be part of a progressive strengthening program when tolerated and appropriately prescribed.

6. Do I need orthotics?

Some patients benefit from arch supports or orthoses, based on individual findings and functional needs.

7. Is it safe to exercise with a painful tendon?

Carefully dosed exercise may be appropriate, but substantial symptom worsening should prompt reassessment.

8. Can it affect both feet?

Yes, although the presentation and severity may differ between sides.

9. Can ankle pain change the way I walk?

Yes. Pain and weakness can affect push-off, balance, and walking tolerance.

10. Will I need surgery?

Many patients are managed without surgery, especially in earlier stages. Advanced deformity may require specialist discussion.

11. How long does rehabilitation take?

Recovery varies with severity, activity demands, and response to treatment; no timeline is guaranteed.

12. When should I see a physical therapist?

Consider an evaluation when symptoms persist or interfere with activity. A changing arch should also be medically assessed.

Schedule an Evaluation

If inner-ankle pain is limiting walking, exercise, or daily activities, contact Nova Physical Therapy in North Hollywood to discuss an evaluation.

Disclaimer

This article is for general educational purposes and does not establish a diagnosis or replace individualized medical advice. Exercise and treatment decisions require an appropriate examination. Physical therapists practice under the California Physical Therapy Practice Act.

References

1. Exercise for posterior tibial tendon dysfunction: a systematic review of randomized clinical trials.
2. AAOS: Progressive Collapsing Foot Deformity.
3. Physical Therapy Board of California: Practice Act.