Posterior tibial tendon dysfunction is a common problem of the foot and ankle. It occurs when the posterior tibial tendon becomes inflamed or torn. This tendon attaches the shin bone(Tibia) to the bone on the inside of the foot. Posterior tibial tendon dysfunction can cause pain and swelling on the inside of the ankle and foot. It can also make it difficult to walk. Posterior tibial tendon dysfunction is often caused by overuse of the tendon. This can happen with certain activities, such as running, dancing, or hiking. Posterior tibial tendon dysfunction is also more common in people who have flat feet or high arches. Posterior tibial tendon dysfunction can also be caused by injury or disease.