Could This Freak Injury Have Been Prevented?


As a musculoskeletal radiologist I diagnose knee injuries and ACL tears on a daily basis.  I’m used to seeing these as grays-scale images on our back-lit medical grade computer monitors, but today I saw an injury happen right before my eyes.

Traffic was light today, and made it to my brazilian jiu-jitsu class early.  Whenever this happens I take the opportunity to get in a little extra stretching and maybe work on some techniques with some of my teammates.

When I was stretching out, I noticed a new person awkwardly standing by themselves against the wall.  I remember what it was like when I first joined the gym and how intimidating it can be, so I’m very sympathetic to new students and guests.

I approached this new person to welcome them and introduce myself.  We got to chatting and it turns out that this was their first BJJ class ever, although they had done various other martial arts before.

Unfortunately they suffered a torn ACL in their left knee a few years back and had to stop.  Now they were ready to get back into things and wanted to try BJJ out.

Class started and the instructor called out the various movements in the warm ups: jogging, skipping, shuffling side to side, back to jogging.

The instructor then organized a class-wide leap frogging warm up.

Imagine doing something like this (without the crawling under the legs part), but with about 20 guys lined up consecutively.

The new student was doing really well throughout the warm up and I remember thinking that they were already fitting in nicely.  Then all of a sudden, when they landed from one of the leap frogs, they fell over and cried out.

They felt a pop in their right knee… their good knee, and couldn’t bear weight anymore.  In fact they had to be carried out to their car.

What a terrible freak accident and disaster for this new student.  My heart sank because I know how long the rehab can be.  It’s a minimum of 9 months before they can get back to regular activities.

I’m willing to bet almost anything that the pop they felt was a torn ACL.

From Snow Orthopaedics.

Image from Snow Orthopaedics.

I couldn’t help but wonder if this could have been prevented with a Functional Movement Screen (I’ve briefly discussed this in a post on Injury Proofing My Body and a post on Sports Injuries).

Gray Cook, the physical therapist who developed this, likes to say, that the biggest predictor for a future injury, is a prior injury.  Our bodies were meant to run, jump, and leap frog without any problem.  The fact that this person suffered such a devastating injury from a simple leap frog indicates that there was likely something else going on underneath it all, and I’m willing to bet the previous ACL tear played a big part in it.

What likely happened was that after the left ACL was torn, this person’s body developed certain compensatory changes.  Maybe they were limping and so one side tightened up more than the other, and the muscles, tendons, and ligaments all shortened… making the muscles, tendons, and ligaments on the other side lengthen.  They also probably developed changes in their motor patterns and proprioception that affected how they moved… and these things weren’t identified and addressed during their rehab.

These compensations eventually lead to increased stress in their right knee, making it a veritable ticking time bomb, so that a simple jump from a leap frog was all that was needed to rupture the ligament.

The Functional Movement Screen is designed to ferret out these sorts of asymmetries in flexibility, strength, and motor patterns, that can develop from prior injuries or just from daily life.

Maybe if this person had undergone a proper screen and cleaned up these issues this could have been prevented, and they could’ve participated in the wonderful class that followed, and developed the same love for the art that I have.

Of course this is all pure speculation, but it certainly makes for a compelling story.

I want to make it clear that I don’t think the FMS is the end all and be all of tests or that it can prevent every possible injury.  I just want to bring attention and awareness to it, to let you know that something like this is out there.

From conversations I’ve had with friends and family and patients and other doctors, people just don’t know about this.

All I want to do is put it on your radar.  Check it out, learn more about it, get tested, and who knows, your ACLs may thank you in the future.

If you want to learn more about it you can go to the website at or pick up these books by Gray Cook: Athletic Bodies in Balance and Movement.


*Image found here.

4 Responses to Could This Freak Injury Have Been Prevented?

  1. May says:

    It make sense. I agree to your points.

  2. Fred says:

    Well like you said, his knee was “a ticking time bomb”. I don’t think there’s really anything you could have done to prevent it (other than, you know, not doing leap frogs).

    • BJJ Caveman says:

      I was hoping with this post to bring awareness to some tools available to help others out there figure out if they have their own hidden ticking time bombs that they can hopefully address before something more catastrophic happens.

      It really was unfortunate for this person… first class too.

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