Could Jamaal Charles’ Injury Have Been Prevented?

The silence at Arrowhead Stadium last Sunday when Chiefs stud running back Jamaal Charles didn’t get up after a play was deafening.  Chiefs fans held their collective breath hoping that he would be OK.  Turns out the fears of Chiefs nation were realized when it was determined that he tore his anterior cruciate ligament (ACL).   He previously tore the ACL in his other knee in 2011 and once again became the stud he prior to that injury once he returned.

The age-old question after tragedy strikes is “could it have been prevented?”   The same is said with many sports injuries too.  Physical therapists, scientists, athletic trainers, and a host of other professionals are constantly researching ways to prevent sports injuries from hamstring strains to concussions to ankle sprains to anterior cruciate ligament (ACL) tears.  Jamaal Charles is an elite athlete and recovered from a previous ACL tear.  He has performed probably hundreds of thousands of the same maneuvers over the last few years since his previous ACL tear.  The play he injured his knee this time was as benign as it gets.  This begs the question if it could have been prevented or if this is just “one of those things” that happens?
Here’s a link to his injury. If you look closely, you can see that after he plants and cuts, his knee collapses inward a little.  That’s when the ACL tore.

How do you tear an ACL?

We know that about 75% of ACL years are non-contact.   We also know from previous studies that there are basically three main ways they tear: planting and cutting, straight-leg landings, and one-step stops with the leg knee fully extended.  Looking at the video, it is evident that Jamaal Charles had the perfect storm – non-contact, plant/cut, straight-leg landing, and one-step stop with the knee extended.

What does the ACL do?

Ligaments connect two bones together.  The ACL resists forward movement of the tibia (“shin bone”) on the femur (“thigh bone”).  The ACL has a huge job – it resists 85% of this movement.  The ACL also protects against too much rotation in the knee.

Why did it happen?

This is a complex answer.   There are numerous factors that have been linked to ACL tears including neuromuscular, biomechanical, hormonal, and structural causes.  For the sake of not making this blog really, really long, we’ll just talk about Jamaal Charles’ situation.  As stated above, the ACL protects against the tibia or “shin bone” from moving forward too far when an athlete plants, jumps, or lands.  When an athlete does these movements, the quadriceps muscles contract, and this contraction pulls the tibia forward.  The ACL is there to protect that movement.  Previous studies by orthopedist Chuck Henning found that there is a “quad-cruciate interaction.”  He found that with the knee extended, like in Jamaal’s case, the load on the ACL increased significantly, providing 85% of the resistive force.  The equation is pretty clear here – rapid, forceful quad contraction + full knee extension + ACL resisting so much of the force = ACL tear.  Henning also found that with the knee in flexion (“bent”), the strain on the ACL was significantly reduced.   In this position, the hamstrings can help “pull back” the tibia, almost like pulling the reins on a horse.  Because Jamaal’s knee was fully extended, the hamstrings in effect, could not do their job and protect the ACL.  The hamstrings truly are the “best friend” of the ACL.

How do you prevent ACL tears?

Complete prevention or eradication of an injury, like most things, is likely impossible.  We know from several previous studies that the best prevention of ACL tears involves a combination of education on proper landing and cutting techniques, strength training, jump training or “plyometrics,” and balance training (Hewett et al, Am J Sports Med 2006).   Numerous studies have found a reduction in the incidence of ACL tears after structured injury prevention programs were completed (Caraffa et al, Knee Surg Sports Traumatol Arthrosc 1996, Noyes et al, AJSM, Mandelbaum et al, AJSM).

Could Jamaal’s have been prevented?

This is an extraordinarily complicated question to answer and keeps the physical therapists at SSOR up at night wondering if there’s anything that can be done for people like Jamaal Charles and every other ACL tear!  As stated previously, Jamaal Charles has likely done this exact movement hundreds of thousands of times and didn’t tear his ACL.   Why this particular play? Why this cut?  Was fatigue a factor?  Did his muscles and nerves not “react” fast enough to engage the right muscles to prevent this?  Did he not “practice” the “right” way to cut?”  These questions are almost impossible to answer and quantify.  We just don’t know.   Yes, ideally he would have cut with the knee flexed and not straight, but plenty of athletes still tear their ACL with the knee bent too.   As a sports medicine community, the more we know, the more we learn we don’t know.
We’re certain Jamaal Charles will be a work horse in rehab to get back on the field again.  We’re hoping for a successful recovery for him.
If you have ACL surgery, look no further than the physical therapists at SSOR to help you get back to work, life, and the activities you enjoy.  We’ve done it for athletes at the highest levels and can for you too.  Give us a call – we have locations in Overland Park and Prairie Village to serve you.