Tendons are the connective tissue that attaches muscle to bone. The posterior tibial tendon attaches to a bone in the foot called the navicular, helping stabilize your arch. Posterior tibial tendonitis is inflammation of this tendon occurring from overuse. This inflammation is caused by extra stress, usually due to a collapsing arch. Because pain occurs along the inside of the lower leg, ankle, and foot, rear foot motion control shoes and motion control or stability insoles are recommended to treat posterior tibial tendonitis. Recommendations: A shoe with good arch support.