A stress fracture is sometimes also known as a hairline fracture or a fatigue fracture. They are very thin cracks in the bone caused by overuse. Here we explain the symptoms, causes and treatment for common sports injuries.
Stress fracture symptoms
Specific symptoms will depend on the location of the injury. However, in general:
- A generalised area of pain which develops gradually.
- You may find a specific area on the bone which is particularly tender to touch.
- Swelling may occur.
- Pain becomes worse with weight bearing activities and decreases with rest.
- Symptoms are often worse at the beginning of a training session, ease when warmed up only to return again later. Pain may start to occur earlier and earlier in your workout.
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 causes a stress fracture?
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, they usually occur in the bones of the legs, not the upper body. This is due to the high forces imparted during weight-bearing activities.
Which sports are higher risk?
They are common in runners, basketball players, and ballet dancers, especially those who increase their training levels too quickly. This is because our bones usually adapt to meet changes in the stresses applied to them. But it does work 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.
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.
Common stress fractures
- Metatarsal – is a hairline break of one of the long metatarsal bones in the foot
- Navicular stress fracture – affects to the navicular (tarsal) bone, causing vague aching pain in the midfoot.
- Calcaneal – affects the calcaneus (heel bone). Symptoms are similar to a bruised heel.
- Medial malleolus– is a hairline break of the medial malleous (bony part on the inside of the ankle).
- Talar stress fracture – affects the talus bone in the ankle.
- Tibia – is a hairline fracture of the tibia bone in the lower leg.
- Fibula – not as common as the tibia but causes calf pain.
- Femur – a hairline break of the thigh bone.
- Pelvic stress fracture – is a hairline fracture of the pelvis bone, often causing hip or groin pain.