Posterior Tibialis Tendon Dysfunction (PTTD)
A Common but Overlooked Cause of Adult Flatfoot & Inner Ankle Pain
What’s Going On?
PTTD occurs when the posterior tibialis tendon—responsible for supporting your foot’s arch—becomes overstretched, inflamed, or torn.
This leads to gradual flattening of the arch and rolling in of the ankle (overpronation), often causing pain and swelling along the inside of the ankle or foot.
It typically affects adults over 40 and is more common in women and people who spend long periods standing or walking.
Common causes include:
- Overuse or repetitive strain
- Flat feet or poor foot posture
- Weight gain or obesity
- Tight calf muscles or Achilles tendon
- High-impact or stop-start sports
- Previous ankle or foot injury
Inflammatory conditions such as arthritis




