Overuse posterior tibial tendinitis is caused by the increased stress placed on the tendon as it tries to compensate for the increased subtalar joint pronatory movement and velocity during physical activity. The stress can cause microtrauma and rupture of some of the fibers of the tendon. This leads to an inflammatory process and the classical clinical signs and symptoms. Therapy is directed at reducing the inflammation, minimizing the fibrosis buildup, re-strengthening the weakened tissue, and controlling the pronatory force. The two case reports illustrate typical clinical signs, symptoms, and treatment for this injury.