Bone Stress Injuries a.k.a Stress Fractures
Have you ever wondered what a Stress Fracture is? Why they occur and what to do about it? Physiotherapist Carla Bywater outlines all the details in Part 1 of this 2 part Blog on all things Bone Stress Injuries (BSI’s)
As summer is well and truly upon us, many, me included, are trying to make the most of the sunshine and extra daylight hours by heading outdoors for exercise. The amount of running trails and routes in Melbourne are endless, so needless to say, sometimes my runs end up longer than expected! As I increase my training load, I am becoming increasingly aware of the risks associated with long distance running, such as bony stress injuries.
In our official first week as Reload Physio in November, we had the privilege to listen to Dr Adam Castricum present on stress fractures and relative energy deficiency in sport (RED-S). Adam currently works at Olympic Park Sports Medicine Centre as a sport and exercise physician.
What are stress fractures?
Stress fractures are overuse bone stress injuries (BSI) that commonly result from a sudden change in training or exercise load. For example, increasing your training volume for a race or starting to train after a period of inactivity – “Hello New Year resolutions!” And in my case, I’ve decided to take my running more seriously again after giving birth to my daughter a year ago.
Why do they occur?...
Our bones are constantly remodelling based on what loads we place upon them. This is a good thing, and usually results in stronger bones. But if we do not allow enough time for our bones to rebuild and adapt after an increase in load, then BSI can develop.
BSI result from the “inability of bone to withstand repetitive mechanical loading, which results in structural fatigue and localised bone pain and tenderness”
There is a continuum of severity with BSI from mild to severe:
Yes, Bone Stress Reactions can develop into a Complete Fracture
Therefore, the earlier a BSI is detected, the better, and the quicker your recovery will be!
Who normally develops bony stress injuries?
Between one to two thirds of competitive long-distance runners or cross-country runners suffer from BSI. Other at-risk populations include competitive track-and-field athletes. Unfortunately, if you’ve suffered from a BSI, the likelihood of it happening again is relatively high (up to 12.6%).
Where do they most commonly occur?
Common injury sites include: the tibial diaphysis (shin), femur (thigh), fibula (shin), calcaneus (heel), metatarsals and tarsals (foot). Less common sites are the pelvis and lower back.
Are some worse than others?
Yes, as mentioned earlier, there is a continuum that your bone injury will fall on. To make things easier a classification system was developed. If we want to get technical, you have high or low GRADE, and high or low RISK.
High or low grade of a BSI refers to how your injury looks on imaging. Has it been present for a short time? Then it is likely a low-grade injury. Or has it been worsening over a longer time period? Which places it into the high-grade category. Classifying it into high or low grade allows us to give you an estimated recovery time. Low grade BSI tend to heal faster than high grade ones.
High or low risk refers to the location of the injury. The location is important as there are certain areas of bone that experience the most tension/load. Treatment of high-risk bone stress injuries are more difficult and require a more aggressive approach to avoid complications. For example, the BSI may develop into a complete fracture, or delayed union or non-union of the fracture site! Ouch!
If a high-risk area is involved, an experienced sports physician will become involved to carry out an orthopaedic assessment. Surgery is a real possibility to fixate the bone in order to promote healing and avoid further complications.
I bet this all seems rather daunting, but do not worry! Healing time frames vary from just under nine weeks (low risk and low-grade BSI) to 20 weeks (high-risk, high-grade). High-risk sites take longer to return to running, regardless of if they are low- or high-grade. It is very important to remember that you and Sally next to you are completely different! Therefore, your return to running timeframes will vary, so don’t try to compare your progress.
As a general rule, at Reload Physio we follow the mantra: “treat the patient not the X-ray”.
“But why do some runners develop a BSI and others not?” You might ask, especially if a similar amount of distance is covered each week.
The answer is multifactorial. Some things are within your control, while others are not. For example, things such as genetics and bone diseases are bad luck and you are not able to change them. While it is easy to focus on the dire, there are other things you can do, or not do, to reduce your chances of developing a BSI.
Because bones are living tissue they respond, and adapt, to the load that is placed upon them. Your running technique influences the amount and direction of force that passes through your bones. If you think your running technique can use some fine tuning it is super easy to get a running analysis done, and to go home with a few things to work on.
Your running program (or lack of) can have a huge impact on your risk of developing a BSI. Have you recently started running from scratch, or increased your running pace, duration or frequency? A significant change in load management is central to disrupting the fine balance between bone ‘building and breakdown’ that occurs on a day to day basis.
Other things we need to think about: your footwear and running surface (trail vs road, or treadmill to pounding the pavements). Neither have been proven to have a direct causal relationship to BSI, however, if either has been changed recently and you have developed bony tenderness, then it is worth looking at as contributing factors!
To reduce your chances of developing a BSI you need to consider the following ‘gems’:
Stay active life long, and encourage your children to do the same, because a longer history of physical activity is thought to be protective against BSI.
Strength training: add this bad boy to your training program to get your muscles stronger to help your bones to absorb ground reaction forces during running. Weaker muscles do not absorb the ‘shock’ as readily and fatigues faster, influencing your technique too!
Nutrition: firstly, you need enough fuel to sustain your training load to avoid a relative energy deficiency. Secondly, your body needs adequate levels of vitamin D and calcium in your diet to support bone health. If we think that this is a contributing factor to your BSI, we will refer you to a dietitian to get the best guidance.
Your hormone and endocrine function are closely related to your energy intake and expenditure. To learn more about relative energy deficiency in sport (RED-S) read our previous blog here.
Avoid sudden changes in loading! If unsure, get professional guidance.
Did you know at Reload Physio we offer comprehensive running analysis, coaching, running technique training as well as movement and strength and conditioning classes to get you back to where you need to be in the future?
Click below to book in for a thorough running assessment by one of our running specialist physiotherapists.
If you feel you may need your running assessed, a training program developed, or need a personalised exercise program to work on your weaknesses, then we have you covered.
If you are recovering from a running related Bone Stress Injury we recommend booking in for a Comprehensive Running Assessment with one of our Physios.