Stress Fracture

What is a Stress Fracture?

One of the most common injuries in sport is a stress fracture. Stress fractures are tiny cracks in a bone. The repetitive application of force causes stress fractures through the bone that isn’t strong enough. Essentially, the bone is weaker than is required for the activity demands or exercise intensity.

The most common stress fractures occur in runners, but stress fractures can occur due to your sport’s demands. e.g. lumbar spine stress fractures in gymnasts and cricket bowlers. Common running stress fractures include foot (navicular, metatarsal), tibia (shin splints).

Stress fractures can also arise from the everyday use of a bone weakened by a condition such as osteoporosis. Overcoming an injury like a stress fracture can be difficult because they usually occur in very active people who hate not to exercise!

Stress Fractures occur in 2 scenarios:

1. Excessive force through normal bone
2. Excessive force through abnormal bone, e.g. Osteoporosis

Stress fractures are most common in the weight-bearing bones of the lower leg and foot. Track and field athletes are particularly susceptible to stress fractures, but anyone can experience a stress fracture. If you’re starting a new exercise program, for example, you may be at risk if you do too much too soon.

What Causes a Stress Fracture?

A stress fracture is an overuse injury. It occurs when muscles become fatigued and are unable to absorb added shock. Eventually, the fatigued muscle transfers the stress overload to the bone, causing a tiny crack called a stress fracture.

Stress fractures often are the result of increasing the amount or intensity of an activity too rapidly. They can also be caused by an unfamiliar surface’s impact (e.g. a runner who has switched surfaces from grass to concrete).
Other stress fracture causes include improper equipment (a runner using too rigid or too flexible shoes) and increased physical stress (a player who has had a substantial increase in playing time).

Where do Stress Fractures occur?

Most stress fractures occur in the weight-bearing bones of the lower leg and the foot. More than 50 per cent of all stress fractures occur in the lower leg. Common sites include:

• Metatarsal (Foot)
• Navicular (Mid-Foot)
• Tibia (Shin)
• The neck of the femur (Hip)
• Pars intraarticularis (Lower Back – Spondylolysis or Spondylolisthesis)

What Activities are susceptible to Stress Fracture?

Sports that involve the repeated impacts of running and landing are vulnerable to stress fractures.

Studies have shown that athletes participating in tennis, track and field, gymnastics, and basketball are very susceptible to stress fractures. In all of these sports, the repetitive stress of the foot striking the ground can cause trauma.

Without sufficient rest between workouts or competitions, an athlete is at risk of developing a stress fracture.

Are Women More Susceptible to Stress Fractures?

Stress fractures affect people of all ages who participate in repetitive sporting activities, like running. Studies have shown that female athletes seem to experience more stress fractures than their male counterparts.

We attribute this higher incidence to a condition referred to as “the female athlete triad”:

• eating disorders (bulimia or anorexia),
• amenorrhea (infrequent menstrual cycle), and
• osteoporosis (reduced bone density).

As a female’s bone mass decreases, her chances of a stress fracture developing increase. The advice of a sports dietitian is highly recommended.

What are the Symptoms of a Stress Fracture?

• Pain with activity is the most common complaint with a stress fracture.
• This pain subsides with rest.

How are Stress Fractures Diagnosed?

During your examination, your health practitioner must evaluate the patient’s risk factors for stress fracture. X-rays may determine stress fracture. Sometimes, the stress fracture cannot be seen on regular x-rays or will not show up for several weeks after the pain starts.

Occasionally, a computed tomography (CT) scan or magnetic resonance imaging (MRI) will be necessary. MRI is the most specific and sensitive test available. A bone scan will identify “hot spots”, which may indicate stress fractures or tumours etc.

How are Stress Fractures Treated?

The most important treatment is rest. Individuals need to rest from the activity that caused the stress fracture and engage in a pain-free activity during the six to eight weeks; it takes most stress fractures to heal. If the activity that caused the stress fracture is resumed too quickly, larger, harder-to-heal stress fractures can develop. Re-injury also could lead to chronic problems where the stress fracture might never heal properly. While you are resting from your sport, it is wise to screen for predisposing factors. We recommend a team injury management approach.

• Sports Physician or Doctor to address bone density, hormonal issues, calcium, Vitamin D etc
• Physiotherapist for whole lower limb and core muscle and joint function
• Orthopaedic Surgeon for surgical intervention if required.
• Sports Dietitian to ensure adequate nutrition.
• Podiatrist for foot biomechanics assessment
• Psychologist to assist with return to sport issues

How to Prevent Stress Fractures

• When participating in any new sports activity, set incremental goals. For example, do not immediately set out to run five kilometres a day; instead, gradually build up your mileage every week. Use the 10% rule.
• Cross-training — alternating activities that accomplish the same fitness goals — can prevent injuries like stress fractures. Instead of running every day to meet cardiovascular goals, run on even days and bike on odd days. Add some strength training and flexibility exercises to the mix for the most benefit.
• Maintain a healthy diet. Make sure you incorporate calcium- and vitamin D-rich foods in your meals. Be guided by your Sports Dietitian.
• Use the proper equipment. Do not wear old or worn running shoes. Be guided by your podiatrist.
• Undertake a Musculoskeletal Screening performed by your Sports Physiotherapist.
• If pain or swelling occurs, immediately stop the activity and rest for a few days. If continued pain persists, see an orthopaedic surgeon.
• It is important to remember that you can return to sports at your normal playing level if you recognise the symptoms early and treat them appropriately.

More Information

Please consult your physiotherapist or doctor regarding the appropriate management of your stress fracture.