This refers to inflammation in the toe extensor tendons that run on the top of the foot and are responsible for lifting the toes up. There are two causes of problems here, one is an overuse injury of the muscles and tendons, which is uncommon, the other is due to tight shoes, or bad lacing causing too much pressure on the tendons leading to inflammation. It usually starts gradually and may initially only be painful in the later stages of exercise. As the condition gets worse the symptoms become more intrusive and may start to interfere with sport and cause pain with day to day activities. You may notice swelling on the top of the foot and areas of tenderness.
If you think you have this condition it is well worth getting it checked out by Mr Willis-Owen. In the mean time you should avoid any aggravating activities which may prolong the problem. It generally won't get better on its own. Anti-inflammatories and ice are helpful after exercise.
Treatment involves first confirming the diagnosis then establishing the cause. Treatment options may include activity modification, shoe or lacing changes, specific physiotherapy, orthotics, and injections. Once you are recovered it is important to address any biomechanical problems or other underlying factors in order to prevent recurrence.
Mr Willis-Owen has suffered with this from time to time and has usually solved the problem with relative rest and tinkering with shoes.