A stress fracture is an incomplete fracture of a bone, sometimes also known as a hairline fracture or a fatigue fracture. They are very thin cracks within the bone and can occur in the Tibia (shin), Metatarsals, Navicular, Calcaneus, Talus, Femur and the Ribs.
Unlike most other fractures they do not occur after a traumatic incident. They are caused by repetitive forces or impact through the bone, over a longer period of time. For this reason, stress fractures usually occur in the bones of the legs, due to the high forces imparted during weight bearing activities. They are common in runners, basketball players and ballet dancers. Stress fractures are far less common in the upper body.
Stress fractures are common in athletes who increase their training levels very quickly over a short period of time. This is because our bones usually adapt to meet changes in the stresses applied to them. This works both ways. Astronauts in space suffer a decrease in bone density as there are no forces in space! If training progresses quicker than our bones can adapt, then this excessive stress results in a stress fracture.
Other risk factors for developing a stress fracture include a poor diet and menstrual cycle disturbances, which make stress fracture particularly common in female athletes.
Symptoms of a Stress Fracture
- A generalised area of pain.
- You may find a tender area to touch on the bone.
- Pain is worse with weight bearing.
- Pain on activity may be worse to start with and then ease before returning afterwards.
- Pain will start to occur earlier and earlier in your workout.
- Pain generally decreases with rest, although may not go altogether.
Stress fractures are diagnosed using a combination of a thorough assessment of the injury and either an X-ray, MRI or a bone scan. X-rays often do not show the fracture itself, but may demonstrate areas where the bone has attempted to heal around it. If inconclusive, an MRI or bone scan may be required.
What Does Treatment Involve?
Treatment of a stress fracture revolves around resting the injured part. If it is a weight bearing bone, then this will usually mean reducing weight bearing. This may be achieved by using crutches or a walking boot. Healing time for a stress fracture is between 4 and 8 weeks. During this time, the activity which caused the injury should be avoided, although other forms of exercise may be undertaken after 1-2 weeks, provided they are pain-free (for example swimming and cycling).
Once the bone is deemed to be fully healed, a return to the aggravating activity can be made, albeit on a very gradual basis. Start at a very low level and slowly increase the duration and intensity, provided you remain symptom free.