Stress fractures are a common injury often seen in military personnel and in athletes or anyone who is subjecting their feet or lower body to overuse. It most commonly occurs in the legs but can occur in other parts of the body. Typical areas for this type of fracture are the leg bones of the metatarsals, the fibula and tibia, with areas higher up the legs much less commonly affected. Stress fractures are caused by repeated stresses to the bone which are not enough to fracture initially, leading to mechanical fatigue of the bone and eventually a fracture.

During activity and exercise there may be an increased report of pain in the part, with patients typically noting they have recently made changes to their training regime’s frequency or intensity. Treatment is typically without complication by reducing the person’s activity or by immobilisation of the part. These fractures heal well in most cases although non-union is a possibility, in which case surgical fixation may be required. Once the fracture is surgically fixed the vast majority of cases heal well with suitable immobilisation.

These types of fractures occur because bone has been loaded again and again and there is rarely any specific traumatic event responsible for the fracture. Bones remodel to reinforce themselves when they are subjected to loads involving tension or compression, with minor damage of the bone occurring due to the stresses. If the remodelling process gets behind as the microscopic bone damage occurs then a fracture can result. The most common occurrence is for the person to have significantly increased their activities recently.

Factors which increase the likelihood of a fracture occurring are reducing the bone area across which the stresses are acting, increasing the absolute levels of force and making the application of such stresses more frequent. The cross-sectional area of the bone is the factor determining the results of force applied, a smaller area meaning a higher order of force is suffered by the bone. Or the force could be increased in itself. Typical examples of risky activities are jumping or running, with other risks being changes in the exercise surface and techniques used.

The important issues in being a risk for stress fracture are assumed to be the mechanical factors already mentioned but there may be many others such as a lower intake of calories, a lower bone density or osteoporosis, female gender and weakness of muscle. An increased incidence of stress fractures occurs in women who run a lot and these types of female athletes and others such as ballet dancers may have menstrual cycle alterations, bone density loss and a typically low body weight so they can easily pursue their activity.

A stress fracture typically comes on without much warning and often without severe symptoms, during an activity of repeated limb loading and without trauma. Resting will usually abolish the pain which will re-appear on performance of the weight bearing activity again. Tenderness and swelling may be apparent locally around the fracture site but it may be two to four weeks before a fracture can be discernible on x-ray. Bone scanning may detect fractures much earlier, within 72 hours of the incident, but are less clear as to the exact cause.

Conservative treatment is the typical management for stress fractures, with stopping or greatly decreasing the troublesome activity over four to six weeks the initial choice. If patients have significant pain on walking they can be given a below knee plaster, a walking boot or a brace for a similar period of time, using crutches if helpful. The use of in shoe orthoses has been studied and found to reduce the incidence of fractures to some degree, with shock absorbing insoles also perhaps helping prevent these injuries.

Most commonly these fractures heal well and without complications but there can be problems with non-union in some particular areas. The base areas of the second and the fifth foot metatarsals are areas which can suffer from poor healing and which should be followed up for more prolonged immobilisation or surgical intervention if they do not heal.

Jonathan Blood Smyth is the Superintendent of Physiotherapists at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for physiotherapists in Brighton visit his website.

• 4 Secrets to Speed Up Bone Fractures Healing
• 4 Simple Tips to Help Heal Fractured Bones
• Stretches for Shin Splints and Treatment
• Osteoporosis Natural Remedies: Effective Remedies
• Understanding of the Complexity of the Wrist Joint