What is the cause of Osgood Schlatter Disease?

Osgood Schlatters is more than just growing pains

To dive into what causes and aggravates Osgood Schlatter knee pain, we need to understand its basic causes.

Put simply, Osgood Schlatter occurs when the bones of the thigh are growing too fast for the quad muscles to keep up.

With every step the athlete takes, the quad muscles are pulling at that attachment, causing pain and discomfort.

The muscle highlighted in the image below is the rectus femoris (part of the quad muscle group). Notice how the lower tendon (in yellow) runs from the quad muscle and across the patella into its attachment site at the top of the shin bone (the tibial tuberosity). Where a tendon connects to bone is called the enthesis.

The rectus femoris, one of the longest muscles in the body and a key factor in Osgood pain

Essentially, we can say rapidly growing bones are the key factor leading to Osgood Schlatter in kids.

Treating Osgood as a tendon injury

But is that the full story?

As much as Osgood is a side-effect of rapidly growing bones, Osgood can be considered an overuse injury of the tendon/enthesis in active children who are not yet strong, mobile, or skilled enough to handle the amount of activity they do.

When we start to think of Osgood as an overuse injury in this way, it now bears similarity to patellar tendinopathy (jumper’s knee). This means we can treat Osgood Schlatter Disease just like a tendon injury - something we do all the time!

This leads to another important insight from the best practitioners working on knee tendon rehabilitation: tendons love consistency.

Another way to say this is that Osgood Schlatter knees hate randomness.

Key aggravators of Osgood

By now, you might be connecting the dots and spotting patterns in your own situation!

Osgood Schlatter Disease consistently affects talented young athletes who are rapidly moving up in their sport. These individuals often encounter similar circumstances due to their success:

• Training frequency changes
• Intensity increase (more running and jumping)
• Changing sports or the addition of a new sport
• Changes in playing surfaces (both harder and softer)
• Shorter rest periods, less time on the bench or sidelines
• Fewer days off between training and games
• Sudden variation in warm-up/cool-down protocols

(Many of the above points are inter-related; taking up a new sport or moving up to a higher team will almost always involve several of these changes!)

It’s typical for Osgood to first start like this. Not surprisingly, we see the biggest surge in new Osgood clients in our gym in the first month back to school from summer break.

We also occasionally see young athletes all but cure their Osgood Schlatters, only to dive straight back into a full training schedule. After many weeks of reduced training during the treatment, their Osgood pain returns simply due to the spike in training load.

Load management and Osgood Schlatter

In sports science there is a concept which encapsulates the above: Load Management. It is also known as the Acute to Chronic Workload Ratio.

Osgood Schlatter Disease responds terribly to poorly planned training load.

Correctly managing load is a balancing act between how much training you have done over the past four weeks (chronic workload) and your current or new activity levels (acute workload).

Keeping these in balance is a big part of my job as a Strength and Conditioning coach.

A typical training load mistake that can lead to injury a few weeks later.

In the diagram above we can see an original mistake of a rapid reduction in training load (like a summer break), followed by a coaching/planning error of increasing training load again too quickly (like a post-summer tournament).

This balancing act of acute and chronic training loads is also why we don’t recommend taking weeks or months of rest with Osgood Schlatter. It makes it so much harder to successfully return to full training in the future.

Instead we recommend a period of relative rest (with a small drop in training and activity), followed by a smooth, gradual return to full sport load.

This can be easier said than done, especially for energetic teenagers who just want to play their sport! Our Osgood Schlatter Disease treatment program outlines the correct load-management scaling at every step of the recovery process to avoid this all-too-common pitfall.

Throughout the Core Advantage Osgood program, a seven-week training program, we guide you on how to get this balancing act right with exercises, warm-up methods, and recovery instructions to get you back to sport pain-free as quickly as possible. We also provide the methods and tools to create consistency in your training week for strong, pain-free knees.

Durham McInnis

Founder and Head Coach · Core Advantage

Our team has spent over a decade rehabilitating growth-related sports injuries in young athletes, and designed the Core Advantage Osgood & Sever's programs.