The ankle joint includes seven bones that join the metatarsal bones of the foot to the tibia and fibula in the shin. When you run, your ankles are flexed and extended through a full range of motion by the various muscles that originate at various points above and have tendons that insert in the ankle or foot bones. All of these tendons are common sites of inflammation in runners.
The peroneus longus and peroneus brevis muscles, which flex and rotate the foot, run down the outside of the leg. Their tendons course behind the lateral malleolus and attach to the underside of the foot. The Achilles tendon, which flexes the foot downward, runs down the back of the ankle from the calf muscles and attaches to the heel bone. The posterior tibialis, which flexes and inverts the foot, runs down the inside of the ankle and its tendon attaches to the arch of the foot.
Posterior Tibial Tendinitis
The main job of the posterior tibial tendon is to support the arch of the foot by exerting upward force. It often becomes inflamed when overworked, as when runners increase their training mileage too quickly. Runners with flat feet or who pronate excessively — that is, roll the foot inward as the foot touches and then leaves the ground in mid-stride — are more susceptible to this injury. Treatment includes resting, icing the tendon and making sure to wear rigid and supportive shoes.
Inflammation of the Achilles tendon is an injury that almost all runners confront at some point in their exercising lives. It is usually an overuse injury that can be caused or aggravated by running faster than usual or doing a lot of running uphill, both of which stretch the calf muscles to the limit. According to the Mayo Clinic, overly tight calves and worn-out shoes are often factors in the development of this injury, which is treated with icing, rest, anti-inflammatory drugs, light stretching and, if needed, steroid injections.
Inflammation of one of the two peroneal tendons on and above the outside of the ankle normally results in a more dull, achy type of pain than the soreness that runners with inflamed tendons elsewhere experience. You may notice what feels like a lump in the area. Pain is usually worst in the ankle but may also radiate to the arch of the foot. According to Northcoast Footcare, walking or running on uneven surfaces or wearing worn-out shoes are the two most common causes of peroneal tendinitis. Treatment includes ice and stretching.