Because our understanding of tendinopathy has evolved in recent years, the condition is now considered a degenerative process; this affects the approach to treatment. Initial therapy should always involve relative rest and modification of physical activity, use of rehabilitative exercises, and evaluation of intrinsic and extrinsic causes of injury. The posterior tibial tendon is a dynamic arch stabilizer; injury to this tendon can cause a painful flat-footed deformity with hindfoot valgus and midfoot abduction (characterized by the too many toes sign). Treatment of posterior tibial tendinopathy is determined by its severity and can include immobilization, orthotics, physical therapy, or subspecialty referral. Because peroneal tendinopathy is often misdiagnosed, it can lead to chronic lateral ankle pain and instability and should be suspected in a patient with either of these symptoms. Treatment involves physical therapy and close monitoring for surgical indications. Achilles tendinopathy is often caused by overtraining, use of inappropriate training surfaces, and poor flexibility. It is characterized by pain in the Achilles tendon 4 to 6 cm above the point of insertion into the calcaneus. Evidence from clinical trials shows that eccentric strengthening of the calf muscle can help patients with Achilles tendinopathy. Flexor hallucis longus tendinopathy is most common among ballet dancers. Patients may complain of an insidious onset of pain in the posteromedial aspect of the ankle; treatment involves correcting physical training errors, focusing on body mechanics, and strengthening the body's core. Anterior tibial tendinopathy is rare, but is typically seen in patients older than 45 years. It causes weakness in dorsiflexion of the ankle; treatment involves short-term immobilization and physical therapy.