Key clinical summary
Posterior tibial tendon dysfunction usually causes pain on the inside of the ankle with reduced arch support, reduced walking tolerance and difficulty with single-leg calf loading.
- Medial ankle pain with a flattening arch or reduced single-leg heel raise strength is a key clue.
- The problem often reflects tendon overload plus progressive loss of foot support.
- Ultrasound can show tendon thickening, sheath fluid and tearing, helping determine how irritable or advanced the problem is.
Typical presentation
Typical symptoms include pain and tenderness on the inside of the ankle, swelling along the tendon, reduced tolerance for longer walks and difficulty with repeated single-leg heel raises.
In more progressed cases the arch shape changes visibly and prolonged standing becomes increasingly tiring.
Why it happens
The posterior tibial tendon supports inversion, arch control and foot stability. Repeated overload, deconditioning, bodyweight load, foot mechanics and age-related tendon change can all reduce its capacity.
As the tendon struggles, the arch may collapse more under load, increasing strain through the tendon and surrounding structures.
Assessment and differential diagnosis
Assessment should determine whether pain is mainly tendon, sheath, joint or nerve-related, and whether there is a dynamic or more established loss of arch support.
Differential diagnosis includes deltoid ligament irritation, tarsal tunnel syndrome, medial ankle osteoarthritis and referred pain from the midfoot.
Where ultrasound helps
Ultrasound can demonstrate tendon thickening, sheath fluid, tearing and dynamic tendon behaviour.
The scan also helps when decisions about bracing, load reduction or guided procedure are being weighed.
Treatment strategy
Treatment usually combines load modification, calf and foot strengthening, arch support strategies, footwear advice and sometimes temporary bracing when symptoms are highly irritable.
In selected cases, injection may be discussed if a specific pain generator has been identified, but the core pathway still revolves around tendon support, gait confidence and progressive strength.
Evidence strength summary
Strongest support
Targeted rehabilitation, sensible load management and diagnosis-led decision making form the core of a strong evidence-based pathway for this condition.
Where ultrasound adds value
Ultrasound is most helpful when the scan result will change treatment, improve diagnostic confidence or increase the precision of a procedure.
Where injections fit
Injections only make sense when a clear pain generator has been identified and the procedure supports a wider plan rather than replacing rehabilitation.
Page-specific FAQs
Is this just the same as having flat feet?
No. Some people have naturally flatter feet without pain. Posterior tibial tendon dysfunction refers to a painful tendon and support system that is no longer coping well with load.
Why is walking so tiring with this problem?
The tendon helps support the arch and control the foot with every step. When it is painful or weak, walking becomes less efficient and more irritating.
Can ultrasound show if the tendon is torn?
It often can, particularly for longitudinal or partial tearing and sheath irritation.
Will I always need orthotics?
Not always. Some people need temporary support while strength and loading improve; others benefit from longer-term shoe or insert strategies depending on severity.
When should progression or deformity be reviewed more urgently?
If the foot shape is changing, walking tolerance is dropping quickly or the tendon is not managing basic load, earlier specialist review is sensible.
Ready for a clearer diagnosis and treatment plan?
Book a specialist assessment, explore the patient hub or review injection options before you decide.
Harvard references
- Myerson, M.S. (1996) Adult acquired flatfoot deformity. Journal of Bone and Joint Surgery American, 78(5), pp.780–792.
- Kulig, K. et al. (2009) Posterior tibial tendon dysfunction: biomechanical and clinical considerations. Journal of Orthopaedic & Sports Physical Therapy, 39(2), pp.79–90.
- Rosenberg, Z.S. et al. (1988) Posterior tibial tendon dysfunction: MR and sonographic findings. Radiology, 167(3), pp.703–706.
What to do next
If symptoms remain intrusive or keep recurring, the next useful step is a proper assessment rather than more guesswork. At Wellbeing & Health MSK Clinics the pathway combines clinical examination, diagnostic ultrasound where it genuinely adds value, and a plan that matches the problem rather than forcing every foot and ankle issue into the same template.
Most patients choose a same-visit diagnostic pathway
For suitable cases we can assess, explain the likely diagnosis, use ultrasound where it adds value, and discuss whether rehabilitation alone or rehabilitation plus a guided injection is the most sensible next step.