The posterior tibial tendon is a little-known, but hugely important anatomical structure along the inside of your ankle. The tendon itself is not much thicker than a pencil, but it plays an essential role in stabilizing your foot. It inserts into your foot along your instep, runs up beside the medial malleolus, the large bump on the inside of your ankle, and attaches to the tibialis posterior muscle, which is buried deep inside your calves. So it attaches the calf muscles to the bones on the inside of the foot and is located at the back of the leg.

Posterial tibial tendonitis is a condition where the posterior tibial tendon becomes inflamed, overstretched or ruptured due to an injury. The posterior tibial tendon provides support to the medial arch of the foot and gives the foot stability when in weight bearing either while standing or walking. 

Posterior tibial tendonitis causes pain or tenderness on the inside of the shin, ankle or foot. It affects the arch of the foot and can cause instability. The patient might not be able to raise their heels and bear their body weight on their toes on the foot which is affected. The pain is usually felt during weight bearing activities and continues to increase with the duration of the activity. 

Podiapro makes custom insoles to help bring about pain relief in cases of posterior tibial tendonitis. By supporting the tendon, the insoles relieve excessive pressure and bring stability to the foot. One of the long term effects of posterior tibial tendonitis is posterial tibial tendon dysfunction where in the arch of the foot starts becoming flat.