Stress Fractures

Discover the causes behind stress fractures, plus prevention and treatment strategies.

by Brad Walker | Updated March 10, 2025

What is a Stress Fracture?

When bone is subjected to stress it adapts and becomes stronger, just as muscle does. However, when the repetitive stress is too great, the bone can become weak and develop small cracks, or stress fractures. This fracture is a result of the bone’s inability to manage the stress over time.

Weakened bones, due to old injuries or other conditions, are much more susceptible to stress fractures because they are unable to manage the new stresses applied to them. Athletes with compromised bone density must be careful when increasing their workload.

Increases in intensity, duration, or frequency can lead to stress fractures due to an interruption in the repair and rebuilding process. The bones need adequate rest time to rebuild and restructure. If unable to repair, the bone will weaken and become susceptible to fracture. Treatment should be started as soon as possible to prevent further damage and a more severe fracture.

What sports and activities are most vulnerable?

While stress fractures can occur in any sport, they are most common in high impact sports of a repetitive nature. Sports such as basketball, track and field, dance, gymnastics, and tennis are all examples of sports with a high frequency of stress fractures.

Athletes in any sport can fall victim to stress fractures if their form, posture, or technique is incorrect or conditions change without a chance to adapt. Changing playing surfaces or using worn shoes, with poor support, can increase the risk as well. Increasing training loads too quickly or changing intensity without a period of time to adapt will make athletes more susceptible.

Anatomy of Stress Fractures

Stress fractures can occur in any bone when repetitive stresses are applied to it, however some bones are more commonly affected than others. Those bones that regularly bear weight, and therefore receive the most shock from high impact activities, are more susceptible.

The tibia (the larger of the two bones in the lower leg, referred to as the shin bone) is the bone involved in the highest percentage of stress fractures. The fibula (the other lower leg bone), the metatarsals (the long bones extending from the heel to the toes), and the femur (the thigh bone) are also commonly involved.

Causes

Stress fractures are caused when repetitive stresses are applied to a weakened bone. This is a chronic injury, which means that it does not happen from a one-time event, but over an extended period of time. Improper equipment (worn or improper shoes), muscle imbalances, or improper running and walking gait can all cause stress fractures.

The muscles are designed to function as shock absorbers during impact activities. They take the stress off the skeletal system and the internal organs. When the muscles become fatigued due to a workload that is more than they can manage, they will no longer be able to function as shock absorbers. The load is then transferred to the bones. The force is transferred through the bone until it reaches a weak area where it causes a small crack. Over time, this can develop into a stress fracture. This process is known as the fatigue theory.

When the human body is subjected to a slight increase in workload it will adapt by getting stronger. The bones, tendons, and muscles will all change to manage the increase. If the workload is increased too quickly the body is unable to adapt quick enough and the stress is transferred to the skeletal system. If there is a weakness in any part of the skeletal system this increase in stress will cause it to succumb to the pressure and crack. This process is known as the overload theory.

Signs and Symptoms

Symptoms of stress fractures are focused to the area of the stress fracture. Pain usually increases with weight-bearing activities and diminishes with rest. Pain is most severe at the beginning of the activity then subsides in the middle of the activity and increases in severity near the end. The pain continues as a dull throb after the activity. Swelling and point tenderness around the site of the fracture may also occur. The pain will gradually get worse and may occur earlier in the workout over time. If left untreated the pain may become unbearable.

Treating Stress Fractures

Rest is the first step in treating a stress fracture. Stopping the activity that has caused the injury and resting the injured area is essential. Ice and elevation are also important in short term treatment. Over the counter NSAID (non-steroidal anti-inflammatory medicines) will help as well.

For minor stress fractures simply resting and avoiding the offending activity until the pain is eliminated may take care of it. However, if the pain returns after re-starting the activity it may be necessary to see a medical professional.

Another helpful method for improved recovery is the use of ultrasound, TENS, and heat. Ultrasound uses high frequency sound waves to stimulate the affected area, while TENS (or Transcutaneous Electrical Nerve Stimulation) uses a light electrical pulse to stimulate the injured area. And heat, in the form of a ray lamp or hot water bottle, is also highly effective in stimulating blood flow to the damaged tissues.

Some stress fractures require immobilization or reduction of weight-bearing stress. An air cast, immobilizing boot, or even crutches may be required.

It is important to keep active during the rest period with no-impact activities such as swimming, biking, or weight training. This will make the return to activity less painful. When it is time to return to activity, usually 6-10 weeks after the injury, it is important to work back gradually and identify the error that originally caused the injury and avoid the same mistakes.

Preventing Stress Fractures

Due to the extended recovery time (6-10 weeks), preventing stress fractures is of major importance. Gradually increasing workloads at a rate of no more than 10% a week and varying the training by using cross training techniques will help to offset the overload and repetition often associated with stress fractures.