Stress Fractures, or bone stress reactions, are common in runners and can plague new and experienced runners alike. This article will shed some light on what these injuries are and how to manage them. 

How do stress fractures occur?

A normal fracture of a bone requires a large force which causes the bone to break. These are normally associated with direct trauma or a fall. By contrast, a Stress Fracture occurs gradually over time and it is due to repetitive load which causes damage to the bone and, in extreme cases, can cause the bone to develop hairline cracks on the surface.

To get a clearer picture in your mind about this type of fracture, you can think of bone injuries in the same way as you would with muscle injuries, which can range from a slight strain to a complete tear. On the one end of the scale is a fracture (or cracked) bone and at the other is bone bruising or irritation.

The human body is well suited to coping with the demands of exercise and, in most cases, regular training will result in our bones actually getting stronger. However, if we apply too much load on a structure (be it bone, muscle or tendon) and do not allow enough time for recovery, injury can occur.

Changes in load can be due to external or internal factors.

External factors include the following situations:

  • increase in distance and/or pace
  • a change from trail running to road running or treadmill running to outdoor running
  • an increase in the number of exercise days in a week, or event
  • cushioning in shoes being worn out.

The internal risks for stress fractures could result from:

  • stiff ankles
  • limited hip extension (a real concern for runners) and
  • muscle imbalances.

These are called ‘bio-mechanical factors’ and have an influence when a runner is fatiguing towards the end of a run. This tiredness can result in the loss of natural shock-absorbing mechanisms and thus increase the load on the bones.
Other factors, like deficiencies in Vitamin D, insufficient sleep or a family history of osteoporosis, can also influence the development of a stress fracture.

Where do stress fractures occur?

The common sites of stress fractures in runners are the small bones of the foot, the big toes and the femur (the long bone of the thigh). The symptoms are pain during activity that settles with rest. There is normally extreme tenderness over the site of injury and there can be some swelling.

Diagnosis with X-Ray and MRI

A normal X-Ray will only show a bone that is broken and as stress fractures are areas of ‘bone stress’, not an actual break, they do not show up on an X-Ray.
If you have a real reason to suspect you may have a stress fracture, do a thorough inspection yourself and then call upon a qualified person to perform their own (objective) examination. During this investigation, the practitioner will palpate the area for tenderness and then ask you to do the ‘hop test’, which can sometimes cause you to experience the same previously-felt pain.
The best diagnostic tool, however, would be an MRI done at your local hospital’s Radiography department. Although this type of examination is pricey for many people, it will show changes to soft tissue and can pick up swelling inside the bone.

Stress fractures and X-Rays or MRIThe photo on the left shows the difference between an X-Ray and an MRI. This runner had been complaining of pain in his second toe when running. The picture on the left is the X-Ray, where the report cleared him of any injury. The photo on the right is a zoomed-in image from the MRI of his second and big toes. You can clearly see that there is a bone injury to the second toe.

How to Treat Stress Fractures

The treatment for a stress fracture is REST! However, the term ‘rest’ is relative – how much rest and for what period is dependent on the patient and the kind of stress fracture. Some people will need to be in a ‘moon boot’ and on crutches for 6-12 weeks, while others will heal with 6 weeks of not running, but may be able to continue with cross-training activities like cycling or water running. Watch the video below on this.

Stress fractures and water running

During the required rest period, the cause of the stress fracture will need to be addressed. A good physio assessment will pick up any bio-mechanical issues that need to be tackled. Your physio will also be able to help you adjust your training programme and give you advice on how to safely increase your pace or distance.

This article was submitted by Shelagh Green, our Associate Manager at the Woodmead Practice. As a trail runner herself, Shelagh is well-equipped to discuss and diagnose a variety of issues relating to sports injuries. If you need some advice in this area, contact Shelagh via our handy appointment form or else speak to your physio.

@function2fitness – Twitter feed
Clinical Sports Medicine 4th Edition – Brukner & Khan