Bone & Joints : could you have a stress fracture without knowing?

In this article, our Head of Virtual Physiotherapy, Will Kenton, reminds us that our bones do far more than hold us up—they protect, produce, and power us every day.

Bone and Joint Action Week is a great time to appreciate the incredible role our bones play for us, both providing support for our movement, protecting vital organs, and being the source of bone marrow that creates the red blood cells we need to live, and as a storage facility for important minerals such as calcium.

As a Physio, it will come as no surprise that we will see plenty of conditions that impact our skeletal system. Sometimes, these injuries can be the result of trauma or a direct blow; other times, the reason for pain or discomfort is less apparent. Cue the annoying stress fracture!

Stress fractures account for 10-20% of all injuries in sports medicine, with a higher prevalence in certain demographics. Military personnel, for example, are at a higher risk due to the volume of physical training and the additional weight of gear and footwear requirements. Females are 2-5 times more likely to develop a stress fracture than their male counterparts, and athletes have a higher risk. That is not to say the average person will not be impacted by a stress fracture. They remain common injuries among many recreational athletes and runners, and identifying the signs and symptoms early can significantly improve recovery times.

What is a Stress Fracture?

The term “stress fracture” can sound a little misleading—after all, all fractures are caused by stress on bones. What we usually mean, though, is tiny cracks or weakening in the bone that come from repeated, low-level strain over time, rather than one big sudden injury.

You can think of it as a spectrum: on one end, there might only be subtle changes seen on an MRI, like bone bruising or inflammation of the bone’s lining. On the other end, if ignored, the stress can build up into a stress fracture.

How Are Stress Fractures Diagnosed?

The most reliable test is an MRI. X-rays are not helpful tools for spotting stress fractures, even after several weeks of pain.

Can You Have a Stress Fracture Without Knowing?

It is possible. MRIs often show stress fractures in people who do not feel any pain, like runners who train regularly. Pain perception is highly individual, so one person may experience pain while another will not notice anything at all. Most of us, however, will likely start to notice some symptoms or changes in our ability to perform our usual exercise.

How Do Stress Fractures Develop?

Bone is constantly breaking down and rebuilding itself, just like every other tissue in the body. Normally, this process remains balanced, a phenomenon known as homeostasis. But if breakdown happens faster than repair, the bone weakens.

Many factors influence this balance, including nutrition, hormones, sleep, training load, age, body mechanics, body weight, and other health factors. Even stress outside of exercise can play a role.

Is It Just a Runner’s Problem?

Not necessarily. While runners often deal with stress fractures, any sport with repeated impact can trigger them. Even a low training volume can cause problems if other risk factors, such as poor sleep or nutrition, are also present.

What are the symptoms of a stress fracture?

These symptoms, while not always present in every stress fracture, are essential not to ignore.

• Pain that feels vague, deep, or hard to pinpoint.
• Pain at rest or at night.
• Local tenderness or swelling if the affected bone is close to the surface (like the shin or foot).
• A sense that your body “can’t handle the activity” anymore.

Sometimes the pain feels as if it is directly in the bone itself, which distinguishes it from pain in muscles or tendons.

How long will my recovery be?

Bone heals fairly quickly compared to other tissues, but it still takes a minimum of six weeks, sometimes longer. An MRI can confirm healing, but this is not always necessary, as improved symptoms and a gradual build-up to tolerating load over many weeks is often sufficient.

During recovery, a period of reduced load bearing if advised, this might be using a boot or crutches to help accelerate the healing process, depending on the location of the stress fracture. It is still important to stay active with safe alternatives so you do not lose all physical conditioning, so working with a Physiotherapist is the first step for many recovering from a stress fracture.

Should I rest for a bit and then start exercising?

No—jumping straight back to old training habits often leads to re-injury. A complete assessment is always the most appropriate first step if you suspect a stress fracture, as often there can be reasons other than training load that might be contributing to your symptoms. Considering all of the below will be necessary:

• Biomechanical assessment with a physiotherapist (especially for runners).
• Checking bone density (DEXA scan) and vitamin D levels, plus using supplements if needed.
• Balanced nutrition is essential, and if absorption issues are suspected, consulting a sports nutritionist can be helpful.
• Careful return-to-training, swapping some running for cycling or other low-impact cross-training.
• Strength training and working closely with a Physiotherapist to build bone density and resilience.
• Prioritising sleep and recovery since this is when the body does most of its repair.

In summary, it is essential not to ignore a nagging new pain in a joint or bone that does not seem to improve or worsen with activity. It is always best to consult with a Physiotherapist who can assess and help understand the best next steps for your recovery.