These are breaks in the bones that occur because of an imbalance of damage and repair. Bones are constantly being 'turned over' by the body, broken down and repaired in a balanced manner. Unaccustomed or very high levels of stress on the bones can disrupt the balance and damage can accumulate faster than the body can repair it. They are generally more common in females and associated with menstrual disturbances ort dietary changes as well as a variety of training factors such as footwear, training surfaces, training volume and biomechanics. These are overuse injuries and can affect a variety of bones in the foot and ankle including the medial malleolus, the talus, the calcaneus, the navicular and the metatarsals.
You will experience pain in the region of the affected bone, initially only with activity, but gradually becoming present at rest. It gets worse over a period of weeks and can cause pain at night, then constant pain. Pain is worse with weight bearing exercise and there is often an area of quite specific tenderness. Certain bones are more commonly affected with certain sports, for example metatarsal stress fractures are more common in distance runners, and navicular stress fractures in sprinters or in jumpers.
If you think you have a stress fracture it is well worth getting it checked as soon as possible by Mr Willis-Owen. You should avoid any aggravating activities with may make things worse. It will not get better on its own, unless you significantly alter your activities. If you try to ignore it, it may progress to a fully displaced fracture which can be devastating.
Treatment involves first confirming the diagnosis which is not particularly easy in the early stages. X-rays may miss the injury and MRI scanning or bone scanning is more helpful. A period of relative rest will be required and this may involve the use of crutches. This will be followed by rehabilitation to work on stretching and strengthening. Non impact training such as aqua jogging and swimming can be a great way of continuing to train whilst the bone heals. It is important to identify why you developed a stress fracture and to identify any underlying problems, which may make you at risk of recurrence.
Mr Willis-Owen has had success using an Exogen bone stimulator to accelerate the healing of his own metatarsal stress fractures 6 weeks before the London marathon and went on to get an international elite time.