Pitching Biomechanics Evaluation

For more than two decades, ASMI has been studying the biomechanics of baseball pitching. The initial focus of these studies was to understand injury mechanisms and provide knowledge to the medical community for improving injury treatment. During the last few years, our purpose has been broadened to include injury prevention. More than 2,000 baseball pitchers from all levels have been tested at ASMI. The wealth of data has led to numerous scientific publications for physicians and others. Biomechanical pitching evaluations are available to baseball pitchers from any level, from youth to professional.

The purpose of the biomechanical pitching evaluation is to reduce the risk of injury or re-injury by addressing the efficiency of a pitcher's mechanics. If a pitcher is able to generate arm speed using his entire body, then less force and torque will be placed on his throwing arm.

To accurately measure and calculate these parameters of human motion, a biomechanics computer program was developed at ASMI. Reflective markers are first placed on some of the pitcher's anatomical landmarks.

The pitcher's motion is then collected by a 3D, high-speed, infrared, eight-camera Motion Analysis System (Eagle digital system, Motion Analysis Corporation, Santa Rosa, CA) that picks up the reflective markers on a computer.

The pitching computer program is then used to calculate the kinematics (body angles, joint velocities, and timing mechanisms) and kinetics (joint forces and torques). Data from an individual's evaluation are compared to cumulative data from a set of elite pitchers previously tested by ASMI. The data is also studied by researchers at ASMI to determine the anatomic comfort of the shoulder and the elbow joints as that individual pitcher throws the baseball. The results of the biomechanical pitching evaluation are based upon the motion analysis data as well as ASMI's knowledge of biomechanics, baseball, orthopaedics, physical therapy, and strength & conditioning. You will receive a 15-page evaluation packet that includes a written evaluation with our comments concerning the efficiency of your pitching delivery and still photos taken of you during your test.

High speed video of the pitcher is also collected using a Vision Research high-speed video camera. This camera records the pitching motion at 450 frames per second (standard video is 30 frames per second).

  • The evaluation will last approximately an hour to an hour and a half.
  • Pitchers will need to wear tennis shoes (preferably turf shoes), socks that cover the ankle, and spandex shorts. If you don't have spandex shorts, ASMI has some for you to use. Don't forget to bring your glove.

ASMI's Dr. Lyle Cain and Dr. Glenn Fleisig on HP Matter

ASMI's Dr. Glenn Fleisig on ESPN E:60

Recent Testimonials

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I just wanted to share something with you guys at ASMI, my son who is a 2018 graduate has been coming to ASMI for the last two years and recently committed to a NCAA D1 school. I provided the biomechanical evaluation from ASMI to the coach and he informed us that he used his evaluation to help him decide on my son. So I just wanted to say thanks for all you guys do there and we will continue to come every year.
--Todd, Collinsville, MS

Before my son and I left for Alabama, I asked him about his expectations for the trip, and he said he thought it would be “educational.” A safe answer, I thought. Perhaps a punt—like many parent/teenager exchanges, right? Well, having now made the trip, his answer was spot on. In your lab, we learned more in one day than we had in pitching lessons over five years. And while all that information can be a bit overwhelming for a 14 year old, he is just old enough to absorb most of it. He wishes everyone could get this level of attention. He told me how he believes he can make his pitching instructor better with what he’s learned. I love that. I hope he’s right that he can be a small agent for change in whatever baseball circles he ends up in. Oh, and he said that he “trusts the scientists.” Despite what he has been told for years about his mechanics, this evaluation taught him what the computer sees, and I think that candid and progressive approach will stay with him forever. He is a good listener. He has been practicing every day in front of the mirror since we got back. Those actions speak for themselves. Once he gets back on the mound in the spring, we’ll see how he incorporates the adjustments. Thank you again for your time and interest in my son. Stay tuned for his updates now that he’s one of your alums!
--Garth, Radnor, PA

I had my son in there for an evaluation and it was very eye-opening to him. Last year, as I pointed out his low elbow and started trying to fix it, he did not seem to have an interest in fixing it. But after the evaluation, it was very apparent that it sunk in how important it was to fix this major mechanical flaw. His elbow is now consistently in the right spot at first impact. His speed has picked up dramatically and his consistency on the mound has been unreal. Some more great news is that the head coach has really trusted the fact that I am looking out for all of the kids' best interest and has fully adapted to my recommendation of rest and throws as well as when to pull the kids out. I have been able to educate him as well as many others based upon the research that you guys have done at ASMI. Funny that we have adapted an attitude of safety first and right now we are on a streak of three straight tournament wins. Other teams repeatedly tell us that we have great pitching depth and wonder how we have done it. Our response, "We take care of our kids and work on their mechanics." So this is to thank you again for the evaluation that you performed on my son and after the season is over, I want to bring him back to see exactly where we are. Have a great day!
--Stephen, Cleveland, TN

Our two days at ASMI were exceptional because of you and your colleagues. You were so generous with your time, and so thorough in your analysis. It was an extremely educational experience for all of us, and thanks to you we have a great deal of information about how he is currently functioning and about where he needs to go from here with his body (and mind!) To say that we were impressed is putting it mildly. What you are doing is phenomenal. To have a concrete grasp of where my son's strengths and weaknesses physically lie is very potent ammunition for him; the clarity and specificity of your feedback made crystal clear what he needs to do to avoid injury in the future and to be the best pitcher he can be. We have already communicated with his coaches and they are very enthusiastic and eager to learn more.

To find out about scheduling an evaluation and/or the cost, please contact Alek Diffenddaffer at (205) 918-2119 or AlekD@asmi.org.

If you have already scheduled an evaluation, click here to fill out the background questionnaire.