Identifying lumbar bone stress injuries in youth athletes: Expert insights

Assessing and treating low back pain is commonplace for many practicing physiotherapists. For the most part, we see the ‘non-specific low back pain’ typology and treat people individually, based on a range of factors which we know can contribute to pain. However, when assessing youth athletes, the game can change – bone stress injuries become a factor which sits in the back of our minds. When much of the research is directed toward anti-diagnosis, anti-imaging and anti-catastrophisation for better outcomes, we really need to know how to differentiate between youth athletes with non-specific low back pain, and those with potential bone stress injuries. This blog will outline the nuances of assessing low back pain in youth athletes so you can produce the most effective management plan for return to sport, and keep young athletes participating in their sport well into their adulthood.

If you’d like to know how the experts assess and manage low back pain in youth athletes, watch Angela Jackson’s full Masterclass HERE.

Understanding the unique challenges

While we know approximately 90-95% of low back pain in adults can be classified as ‘non-specific’, it’s different for youth athletes – approximately 73% of low back pain in youth athletes can be classified as having a specific cause. That’s a huge difference. So while we may not diagnose and scan many backs we see in the clinic, our perspective may need to shift when assessing youth athletes with low back pain.

Other considerations for youth athletes is that their backs are a little different; their intervertebral discs are more elastic, while this may help to reduce the risk of disc injuries, it can result in more stress on the neural arch and potentially contribute to a higher risk of bone stress injuries. Interestingly, the pars interarticularis does not mature until approximately 25 years old – so our understanding of a ‘youth athlete’ needs to consider people up until this age.

The subjective assessment is key in understanding the patient’s injury, however the relative lack of life experience for youth athletes can mean they may not have experienced pain before, they may not have a vocabulary to explain pain and therefore might not explain the features of their injury in the way we are looking for – a more direct line of questioning might be required, as well as follow-up questions to learn more about the patient’s pain experience.

Identifying bone stress injuries

It’s estimated that in extension-based sports, for adolescents who have had more than two weeks of low back pain, approximately 40% will exhibit spondylolysis on scans (1). This is a high number and needs to be in the back of our minds when managing young athletes. Spondylolysis can be considered as a spectrum of bone stress injuries from bone marrow edema to spondylolisthesis. For kids, it most commonly occurs at L5, due to the anatomy of the sacral angle and the inferior facet of L5 causing a large anterior shear on the pars. But how do we know when we are dealing with a bone stress injury, versus non-specific low back pain? The management can be quite different, and it’s often a balancing act of appropriately managing back pain while avoiding catastrophisation.

Angela Jackson outlines some key differences in her Masterclass. For bone stress injuries you are looking for localised, unilateral pain which is worse in extension or lateral flexion activities and eased with rest. While in non-specific low back pain, iit is more likely the patient will complain of pain aggravated with flexion-based activities or sitting, and they are more likely to have pain at rest. Notably, there are no objective measures for bone stress injuries, so you really need to make sure you can gain a good understanding of the patient’s condition before you move to the objective assessment.

See Angela explain the different grades of bone stress injury on scans in the below video taken from her Masterclass:

Subjective assessment

As mentioned above, there are no specific objective measures we can use to identify bone stress injuries in youth athletes, so it’s important to gather a lot of information in the subjective. Obviously, you want to learn about their aggravating factors, learn about their sports(s), and the amount of load completed per week. Some key findings in the objective which may point you in the bone stress direction are localised/pin-point pain, it can be intermittent at the start and then worsens as it progresses, and it’s made worse by activity and eased by rest (this is a key difference between non-specific pain versus bone stress). You also want to get a good understanding of the patient’s recent growth, as a speedy growth spurt can contribute to the overall picture. Also, it can be useful to get a gauge of non-sport related factors such as diet and hormonal changes which may affect bone turnover.

Once you have a good picture of the patient’s condition and current lifestyle, you need to hone in on what has changed in their load to help guide management decisions. This is common for us physiotherapists, in most situations we are really trying to identify what has changed over time – but it is particularly important to identify the cause of bone stress injuries so you can manage them appropriately. You want to know about factors such as the number of sports/activities, type of activities, hours per week, intensity and level of play to understand the amount of load the athlete is under and what may have contributed to the injury over time.

Objective assessment

There are a few things which can point toward bone stress injuries when completing your objective assessment. Firstly, when assessing range of motion, the patient is more likely to be aggravated by extension and lateral flexion (ipsilateral i.e. compression-type pain), you may find quadratus lumborum and paravertebral muscle spasms which can often be both sides, reduced thoracic and hip rotation range of motion, and they may be painful on a single leg bridge. Additionally, they may have reduced latissimus dorsi mobility and control – watch the below video taken from Angela’s Masterclass where she demonstrates how she would assess this:

Wrapping up

Early identification of low back bone stress injuries in youth athletes can be the key to reducing time on the sidelines. Optimising your assessment and knowing what you’re looking for can put you in the best position to help your patient get back to sport as soon as possible, and continue a long career into the future.

Watch Angela Jackson’s full Masterclass HERE for expert insights into the assessment and management of low back pain in youth athletes.