Bone Stress Injuries

Bone Stress Injuries

With athletes entering the new year, it is common for a physiotherapist to see an increase in Bone Stress Injuries. The most commonly recognised of these injuries being a Stress Fractures. 

Over the coming weeks, we will outline: 

  • Factors that contribute to the development of bone stress injuries
  • How coaches and athletes can identify the early warning signs and how a diagnosis is confirmed.  
  • The difference between low and high-risk stress fractures. 
  • Finally, we will look at what steps are effective in managing these injuries when they do occur. 

What are Stress Fractures?

Most athletes and coaches have heard about stress fractures.  Indeed many will have suffered them at some stage in their career. However, Bone Stress Injuries are often not well understood. In an acute fracture, the force applied exceeds the capacity of the bone. The bone fails and fracture results. In stress fractures, the frequency with which load is applied is more significant than the size of the force. Repeated loading of the bone without adequate recovery, results in subsequent failure. 

Bone, like most tissues, undergoes constant remodelling. This remodelling allows the bone to respond and recover from the demands of life, training, and competition. This remodelling takes the form of the removal of damaged bone and the restoration and repair of the affected area. Bone stress injuries are a disruption of this process.

How do Stress Fractures develop?

Stress Fractures represent a late stage, in a spectrum of injuries. This spectrum of injures are collectively called Bone Stress Injuries. At the other end of the spectrum is Bone Marrow Oedema (BMO). Bone Marrow Oedema is a finding observed on medical imaging and is not often associated with pain. It is however frequently found in various bones of active people, feet and shins of runners, backs of tennis players and cricket fast bowlers. The development of Bone Marrow Oedema is a necessary step in subsequent stages of Bone Stress Injury and when found on imaging should be a prompt for the careful review of training loads even when asymptomatic.

Continued application of loading above the ability of the body to recover will result in the progression of BMO to a Bone Stress Reaction and subsequently, Stress Fracture. It is often only once Bone Stress Injuries have progressed to a Stress Reaction that they become painful. Given this, athletes and coaches need to realise that even where symptoms are new, the process driving their development has often been long-standing.

What factors contribute to the development of Bone Stress Injuries?

The development of bone stress injures arises from an imbalance in loading and recovery. As such, any factor that results in higher load or reduced recovery can contribute to the development of bone stress injury. While training load is a significant factor so too is the ability to recover. Factors that impair recovery such as sleep or energy deficit, systemic illness, and dietary deficiency, can all contribute to the development of bone stress injury. 

In managing an athlete presenting with a bone stress injury, modifying training loads may well be a necessary step. However, failing to identify other, recovery-related factors will ultimately either result in injury recurrence or diminished training capacity. It is for this reason that when working with an athlete presenting with bone stress injures I am a strong advocate of seeking input from medical and dietary professionals. 

That’s all for today, next week, we will look at what coaches and athletes should be looking out for and how a formal diagnosis is made. 

Until next time, happy training.

Michael Hedger