Peroneal tendinopathy is an uncommon problem with the tendons on the lateral side of the ankle joint. The condition in most cases happens in runners in which the loads on those tissues are so much higher. There are 2 peroneal muscles on the lateral side of the lower limb whose tendons go round the outside of the ankle joint with one tendon attaching on the outside of the foot at the bottom of the fifth metatarsal. The other tendon goes under the foot to connect to an region near the center of the arch of the foot. The peroneal muscles have many different functions, but a major one is to counteract the rearfoot rolling laterally and winding up with a sprained ankle. As they work hard at that action, the stress on the tendons could be too much for the tendon to take and they are prone to peroneal tendinopathy.
Normally the tendinopathy starts off with discomfort either over or just below the outside ankle bone with or without some swelling. In some the inflammation develops later. With ongoing exercise the symptoms gets more chronic and gradually worse. A typical feature in those with peroneal tendinopathy is a low supination resistance. This means that it's easy for the rearfoot to supinate or roll laterally. This leads to the peroneal tendons to be really active, so if you then combine it with higher level of sporting activity, then the tendon is at high risk for an overuse injury.
Dealing with Peroneal Tendinopathy generally begins with minimizing the load by reducing physical activity levels as well as the use of footwear wedging or foot inserts to pronate or tip the foot inwards so the muscle does not have to function as hard. Ice and anti-inflammatory medicines could also help decrease the pain and inflammation. Over the medium to long term increasing load by the way of exercise ought to be put on the tendon so that it can get accustomed to the loads placed on it. In some circumstances, surgery is recommended.