Bone stress injury represents the inability of a bone to withstand repetitive loading from weight bearing activities, such as running, jogging and jumping sports. Bone is in a constant state of turnover, a process called ‘remodelling’, which means new bone develops and replaces older bone. This enables our bones to adapt and cope with different loads we put them through.
Overuse bone stress injuries occur when excessive load or activities are repeated so often that weight bearing bones to not have enough time to ‘remodel’ between exercise sessions. Examples can be a sudden change in training volume or intensity of running or a lack of recovery between training sessions. This results in an imbalance in the bone remodelling cycle and weakness can develop.
This can cause a spectrum of injuries, from bone stress to stress fractures which is a small ‘crack’ in the bone. Symptoms are dependent on the degree of injury to the bone, but typically people have pain with weight bearing activities (such as running and jumping) and localised swelling and tenderness over the affected bone. As bone stress injury increases, people can develop pain with walking, as well as at rest.
Lower limb stress fractures are more common than upper limb and the most frequent bones affected are the lower leg (tibia), followed by the weight bearing bones of the foot (metatarsals) and smaller bones of the mid foot. It is important that the symptoms are identified early, as a bone stress injury can recover relatively quickly if it is off loaded as soon as symptoms develop. However, if the affected bone continues to be overloaded (such as with running) and not enough time is given for it to recover, then a stress fracture can develop.
In my clinic, I treat patients of all ages and sporting ability, as these injuries can develop in both recreational and high-level sports men and women alike. It can happen in someone who has started a new exercise or running programme as well as an experienced runner who has increased their mileage and not allowed for adequate recovery between training sessions.
The majority of people who develop bone stress injury do so from overuse and we always need to consider a person’s training regime, and overall general conditioning to understand why they have developed an injury. In addition, there are certain groups of people that can be more prone to developing a problem, including those with low bone density, women with irregular or absent menstrual cycles, those that have suboptimal nutrition for their level of sport and certain medical conditions that can affect bones or lead to reduced absorption of Vitamin D and calcium.
Typically, patients visit my clinic with activity-related pain and soreness over the affected bone area. During the first appointment, we discuss how your symptoms developed, including any sporting activities or changes in physical activities preceding your symptoms. We then evaluate if you have any risk factors that may make you more likely to develop a bone stress injury.
In the majority of people, we will undertake routine blood tests looking at your bone profile, which includes your calcium and vitamin D levels. In some cases, we will also screen for any associated medical conditions that may be affecting your bones. This can include looking at levels of female hormones of the menstrual cycle.
We undertake a full physical examination, looking at the affected bone, as well as assessing if there are any biomechanical or joint/muscular issues that can predispose to the injury.
Typically, most people require further imaging, such as an X-ray or MRI scan to assess the degree of bone stress and to evaluate for a stress fracture. If clinically, a stress fracture is suspected at the first consultation, we will offload the bone using a boot walker (and sometimes crutches) whilst we wait for the scan results.
Once a bone stress injury is confirmed, a period of ‘offloading’ in a boot walker is started. This takes the weight off the bone and allows time for it to heal, the duration of which is dependent on the bone affected and the level of bone stress involved. This can vary considerably from a few weeks to months. However, during this time, we will start physiotherapy rehabilitation, which is progressed gradually as symptoms allow.
Pain is used as a guide for your level of loading and fitness can be maintained with less load-bearing exercise, such as aqua jogging and static cycling. Additional therapies can also be utilised, including hydrotherapy, muscle stimulator machines to maintain strength, and in certain prolonged cases of stress fractures, we can use bone stimulator machines.
Once you are able to begin weight-bearing again out of the boot, we undertake a very progressive return to your sport, often starting on the anti-gravity treadmill, for example. It is important to return to your sport safely and we often work with additional clinicians such as Consultant Orthotists, who will look at your running biomechanics and foot posture.
In addition, if any risk factors are identified, we can work with our sports nutritionist to optimise areas of your bone health, such as Vitamin D deficiency. In some cases, further specialist reviews and investigations are required if there are any underlying menstrual problems that we feel may be affecting your bones.
Following your initial treatment, we suggest regular follow-up appointments to assess your progress and plan your rehabilitation and return to sport safely. The recovery time is dependent on several factors, including the location of bone and extent of bone stress, how long you have had your symptoms and whether there are any specific underlying risk factors that we need to address.