Bone injuries caused by running are usually stress fractures. A stress fracture is a partial or complete fracture of a bone due to its inability to withstand repetitive forces.

Injuries to the bone caused by running are usually stress fractures - a partial or complete fracture of a bone due to its inability to withstand repetitive forces.

Stress fractures mainly occur because of bone fatigue, abnormal mineral content or stiffness. Runners may succumb to fatigue stress fractures due to increased training or when new training methods are introduced. When fractures are caused by normal forces that act upon bone which has abnormal mineral content or reduced elastic resistance (stiffness) they are called insufficiency fractures.

Stress fractures in the small bones in the toes are common in runners (particularly 3rd and 4th toe bones and sometimes the little toe) and the leg bones below the knee (tibia and fibula). Less common areas of stress fractures include the small bones in the foot, including near the ankle (talus) and heel (calcaneus), in the knee cap (patella), the bone that runs from the hip to knee (femur) and bones in the pelvis (pubic rami, sacrum).

Symptoms

• Pain associated with running and relieved by rest.
• Tenderness of the bone in cases where the fracture is superficial.
• A pain crescendo effect i.e. the pain comes on earlier and earlier within a run and eventually does not go away at rest.

Causes

• Repetitive loading over long periods with high frequency.
• Excessive running on harder surfaces.
• Training errors.
• Amenorrhoea (decreased oestrogen levels causing reduced bone mass) in female runners.
• Excessive running during first six months following childbirth or when breast feeding.
• Biomechanical or structural anomalies i.e. narrow tibia bones, low arches of the foot, hips that do not move correctly.
• Inappropriate or worn out footwear.

Self help

Once a stress fracture has occurred the best thing you can do is follow the advice of your practitioner. General guidance would be as follows:-

• minimise weight bearing especially during the first 2-3 weeks (it is unusual for people to go non-weight bearing (e.g. use crutches) but there are situations where this may be helpful for a period of time)
• maintain a good regular diet, high in calcium
• take calcium, magnesium and zinc supplementation
• take homeopathic medicines such as calcium phosphate and symphytum
• ask your practitioner about use of magnets over the site of pain (this can help recovery)
• maintain flexibility, mobility and strength where possible without loading the fracture site
• maintain cardio-vascular fitness using non-loading activities such as swimming or running in the water. Be careful when getting in and out of the pool and do not push off from the side.

Treatment

If functional or structural anomalies such as stiffness or tightness have caused the injury, then your therapist may work to loosen stiff joints and release tight or over-worked soft tissues. If muscles have been working in the wrong patterns then exercise re-education and rehabilitation may be needed.

Certain structural anomalies of the feet, contributing to stressful patterns of movement of the foot, above the knee, or at hip or pelvic level may need support from shoe inserts (functional orthoses) or modified insoles. Advice and guidance will be necessary about when to start running again and how to build gradually back up to normal training loads.

There are no specific clinical tests for stress fractures that give conclusive evidence. Therefore other possible causes of bone injury will need to be considered such as local inflammatory muscular or joint problems and rarely, but possibly, bone tumours.

The injury will be diagnosed in two ways:

• Clinically - by examining the history of the injury, site of pain and absence of muscle or joint problems and
• Objectively - by further investigations via special scans such as 'radio-isotope' bone scan, 'CT' or 'MRI' scanning.

Note - stress fractures do not generally show up on 'normal' X-Rays for at least 3 weeks and even then the angle of the X-Ray can occasionally miss them.

Average recovery time

If the injury is caught and preventative steps taken before a stress fracture actually occurs, recovery time will be approximately three weeks. Average recovery time for a fatigue stress fracture is 5-8 weeks, occasionally longer. For an insufficiency stress fracture, the average recovery time is uncertain, but may be longer than 5-8 weeks due to abnormal mineral content of bone, with possible delayed recovery time.

Prevention

• Avoid training on hard surfaces where possible.
• Introduce a degree of cross training to avoid unnecessary loading.
• Wear good shoes and replace them as soon as they are worn out.
• Work on mobility, flexibility and strength.
• Have a biomechanical analysis.
• Get regular self/professional massage.