Pitching Mechanics and Injury: Are We Forgetting Something?

By Dr. Stephen Osterer (@drsosterer)

How most view pitching injury:

Ask most pitching coaches at the amateur or even collegiate and professional levels about injury prevention and you’ll find the conversation default to mechanics. Where the elbow needs to be, how long their stride length should be compared to their height, or having their head in ‘XYZ’ position at late-cocking. Indeed, biomechanics provides us with a large pool of information. So large, in fact, that sometimes we blind ourselves to the rest of the pitching injury paradigm. However, the complexity of the biological system cannot be dwindled down to biomechanical analysis, as it is just one component of athletic performance. Let’s step back from this narrowed viewpoint and consider what we are gaining from breaking down pitching mechanics and what other pertinent information we may be skipping over along the way.

Mechanics 101

The most significant information that has been deduced from biomechanical research is the amount of stress and/or strain placed on biological tissues while undergoing certain movements. By throwing with X kinetic and kinematic factors, scientific researchers are able to calculate the amount of force being placed on Y. This information is subsequently used to make mechanical tweaks in an effort to decrease the physiological burden on a specific anatomical region/structure/tissue/cell and so forth. Being up to date on current information is incredibly important when dealing with injury prevention and performance in baseball; pitching is violent in nature and players are increasingly getting injured. (As pitching coaches, we have a responsibility to help prevent this).

For example: a pitcher has a long history of shoulder pain and shows excessive contralateral tilt while throwing. According to the research, it would be prudent to alter this mechanical flawin order to decrease the load on the shoulder. Problem solved right?

What are we missing?

Biomechanical insight provides us with parameters that assist in understanding which mechanics CORRELATE to POTENTIAL injury. Notice that I did not say LEAD to DEFINITE INJURY. Though somewhat minute in stature, this small difference is sometimes painstakingly neglected in the dogma of baseball culture.

Youre going to injure yourself if your elbow/shoulder/wrist/head/trunk/pelvis/knee/foot/belt/shoelace/hair is in that position!!!No. The literature does not claim that universally. In fact, it simply provides us with information regarding the demand being placed on a tissue. Different demand for different kinetics and kinematics. That’s it.

Interpretation of this demands contribution to overall injury is, actually, fairly simple. Essentially it all comes down to the following:

Demand > capacity = Injury

Demand < capacity = Adaptation

Capacity >> demand = Prevention

In other words, in order for an injury to occur, the demand (or load) on a tissue must greatly outweigh it’s capacity to handle it. Lower the demand, and you get an adaptation over time.

As you can probably see, biomechanical information is not the be all, end all, of the injury equation. Rather, the demand component is just one piece, and includes more than just biomechanics. Granted, significantly changing a pitchers mechanical red flags can greatly reduce overall demand. But so can increasing rest between outings, decreasing how many pitches are thrown per game, and altering the intensity of throwing between starts. This list can go on forever, as I’m sure most of us could continue to provide other factors at play. And that is exactly the point. It’s never one thing that leads to injury. Biomechanics alone is not the answer. It doesn’t even make up the entire demand component!

How much attention are we really paying to the capacity side of the equation?

How many pitching coaches approach the months leading up to the season as a time to progressively build their pitchers’ tissue load bearing capacity? If we know that a pitcher is prone to shoulder pain from excessive contralateral tilt, then why not also focus on building the affected tissues’ strength? Developing a safety net, so to speak. How about a pitcher who always had medial elbow pain?

The question, in my opinion, eventually becomes: over time, can we gradually increase the strength of the ligaments, tendons and bones? My answer: Absolutely!

In the manual therapy world, it is recognized that function dictates anatomy. Our body has an incredible ability to adapt to the demands that we place on it, and that most definitely includes the functionality of bones, ligaments, tendons and muscles. Check out this example of a fibula reorganizing and remodeling itself to fit the demands of the system.

What happens when we do the opposite and stop physical activity and, therefore, loading of our tissues? Sarcopenia. Osteopenia. ATROPHY. If we can all understand the concept of ‘use it or lose it’, then why are we so averse to the opposite? Why is it so common for overhead throwers to have humeral retroversion? Again, function dictates anatomy. Our body will adapt to the demands placed on it, granted we do not demand too much.

It is beyond the scope of this article to outline how we can go about building tissue capacity, but an understanding of progressive overload is a good place to start. Adaptation is a constant biological process that cannot be trivialized. Rather, in a sport where non-contact injuries define it’s culture, this process demands respect. We have a fairly good idea what type of mechanics lead to increased strain and stress on various aspects of our biological system. Although important, we must remember that this is but one aspect and that we cannot forget about load bearing capacity. Improving our tissues load bearing capacity is another way to prevent injury that as a baseball community need to collectively become better at.

Baseball Performance Group



  1. DR. Osterer.
    Your articles are very informative.
    {Prevent}, {avoid} or stopping from happening.{To make impossible.}
    You mention injury prevention which is not possible due to the fact that every time one throws an object one’s arm is susceptible to injury possibly leading to surgery we can only hope to minimize the possibility of injury by incorporating a constructive physical program along with learning how to execute proper body movement from the rubber to stride foot touch, plant down and leg stabilization then on through hip to shoulder separation which carries on the momentum created while stroking away from the rubber on to ball release and follow through, these body movements are a series of sequenced chain reactive body movements to be executed at the proper time in their proper sequence.
    As DR. James Andrews recently stated without proper body movement mechanics little else matters in one’s effort to minimize the possibility of chronic sore arms and injuries leading to possible elbow and shoulder surgery.
    These sequences of body movements are very instrumental in allowing the body instead of the throwing arm to absorb the brunt of the physical action created by the violent throwing action/movement of the arm and all other body parts effected during the throwing movement.
    Looking forward to reading more of your articles.
    Don Ervin

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