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Zach Eflin’s mechanics may increase his risk of chronic back injury

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“Never let the fear of back pain get in your way.” - Babe Ruth... I think.

MLB: Philadelphia Phillies-Workouts Bill Streicher-USA TODAY Sports

Some mornings I look at my reflection straight in the eye: “if Zach Eflin debuted in the majors at age 22, then what am I doing? Am I successful? I’ll tell you one thing, today is the day you shave that quarantine beard.”

We often elevate baseball players on a pedestal to marvel at their work ethic and talent. Sometimes it’s hard to even think of qualities we have in common with ballplayers - we both own sunglasses? we eat at restaurants? we both swing at and miss pitches at an obscene rate (@Jorge Alfaro shots fired)?

Another exciting quality you may not have realized you and some of your favorite ballplayers share is chronic work-induced low back pain. Yep, just like Zach Eflin up to an estimated 84% of adults suffer from low back pain at some point in their lives. Sure, some of us sit in a chair all day but if the endpoint is chronic low back pain, aren’t we the same, Zach?

Last season Eflin went on the 10 day DL with back tightness. Again, to begin this season, Eflin is sidelined due to “back spasms.” What does this mean? Will this be a recurring issue? Below I am going to explore Eflin’s injury to understand a) how ballplayers develop back injuries, and b) how Eflin’s mechanics might predispose him to continued back issues.

Low back issues in baseball

The prevalence of low back pain in baseball players at all levels is estimated to be somewhere between 3 and 15%. The main mechanism of injury is related to the things that, well, baseball players kind of do a lot : hitting and pitching. For the purpose of this article, I am going to focus on pitching-induced back injury.

The entire pitching process is a complex series of well coordinated movements that culminates in an explosive action to deliver the ball to home plate:

Ideal mechanics effectively transfer energy from the legs, to the torso, to the arm. Timing each movement perfectly minimizes stress on each part of the body that is involved in the pitching motion. This concept of coordinated muscle/body movements that culminates in a pitch being thrown is known as the kinetic chain, and there is a growing body of research analyzing how optimizing a pitcher’s “kinetic chain” can decrease risk of injury.

The timing of pitching movements is especially critical to the back, as the rotational and torsional motion of pitching puts significant strain on the lumbar spine (lower back). If rotation of trunk and torso are not in synchrony with each other and the pitcher’s arm the risk of injury is predicted to increase.

In one article discussing chronic lower back pain in baseball players, the authors included image captures of different pitchers to show how certain mechanics could predispose someone to injury. Below are two images directly from the paper:

In the paper, Image “A” is described as an example of ideal mechanics. Why? The key is energy transfer. You can essentially draw a straight line (with a slight curve at the knee) between the pitcher’s right ankle and neck, which illustrates how synchronously his body is working to generate the energy necessary to pitch. This decreases the overall strain on each individual part of his body.

In image “C”, however, we see a pitcher with improper mechanics who is increasing strain on his lower back. If you look closely, you will notice that the pitchers spine is extended, meaning it is curved towards home plate. The reason the pitcher is extending his lumbar spine is because he needs to generate energy that he has lost due to poor energy transfer earlier in his delivery. Here is the author’s description of this “lost energy” directly from the article:

“Failure to appropriately engage the musculature of the lower extremities and hips during the push off through maximum external rotation decreases the energy transfer into acceleration, ball release and follow-through phases. This necessitates compensation by the torso and upper extremity musculature to exaggerate lumbar extension to develop this energy. If trunk extensor–flexor muscles lack adequate strength and power to control the forces that develop in the lumbar region .. there is potential for lower back pain onset.”

Essentially, if you are not appropriately engaging your legs and hips early in your pitching motion you lose energy and have to compensate later. One of these compensatory mechanisms is lumbar spine extension, which increases strain on the back, and therefore increases injury risk. What does this all mean for our friend Zach Eflin? .

Zach Eflin’s mechanics

We can take a look at a few Eflin pitching stills to determine if he exhibits improper mechanics that could predispose him to back injury. Below I took two separate stills that exhibit concerning body positioning:

As you can see in the above pictures, Eflin’s trail leg is bent and he is extending his lumbar spine toward home plate similar to figure C above. He appears to be improperly transferring energy from his legs, to his torso, to his shoulder/arm necessitating him to compensate. He does so by extending his lumbar spine in an effort to generate the energy he has lost earlier in his pitching motion. This puts unnecessary strain on his back predisposing him to back issues.

Eflin has had at least two instances of back pain necessitating time off over the past year and we have a clue to its cause. In order to prevent further back injuries he will have to either strengthen his core, lumbar, and pelvic musculature to compensate or adjust his mechanics.

Now, this analysis is certainly not perfect. For one, I am analyzing Eflin’s body positioning while he is wearing a jersey. If anyone knows of any shirtless Eflin pitching videos, please send them my way. Second, understanding how pitching mechanics lead to injury is still an inexact science, but, again, there is strong evidence that improper mechanics do predispose a pitcher to injury.

What does this mean for Eflin? Given his dodgy injury history it could mean quite a lot. As he progresses throughout his career he may need to make adjustments to his pitching motion to decrease the strain it causes on certain parts of his body - but for this weird and short Philadelphia Phillies’ season? We can only hope he stays healthy.