Motion analysis technology sheds light on how major league hurlers can improve performance

Ask Glenn Fleisig, Ph. D., why he built a regulation pitching mound in his Birmingham, Ala., complex, surrounded it with a series of high-speed video cameras, and talks grown men into dressing in Spandex bodysuits, and his answer is simple: protection and performance.

Evaluation of a hurler’s biomechanics lets coaches identify problem areas in pitching motion that could cause injuries and ways to improve performance. Photo courtesy of American Sports Medicine Institute.

Fleisig, the Smith and Nephew Chair of the American Sports Medicine Institute, is a pioneer in the use of video and computer technology to study the pitching motion of baseball hurlers as they go through their windup and delivery. With the assistance of six high-speed video cameras strategically placed around the mound and a computer for analysis, Fleisig identifies any “weak links” that might exist in the kinetic chain required to throw a fast ball, curve or change-up.

“There are two reasons to study biomechanics in this way,” said Fleisig. “First, by studying how a pitcher pitches, we can improve safety. No. 2., if you If you watch the motion, you can improve the pitcher’s performance.”

Observing a pitcher at a practice or in a game reveals little more than a blur and a vague sense of what’s happening. But at the non-profit institute, Fleisig’s six cameras shoot 240 frames per second each in a synchronized way to reveal the subtleties of the kinetic chain.

“We have about 35 different checkpoints in pitching mechanics,” Fleisig explained. “When you pitch, you just don’t use your elbow and shoulder. You use your whole kinetic chain. We look at the whole chain for any weak link, like rotating the hips too soon or bending the elbow too much.”

To identify those checkpoints, pitchers don Spandex bodysuits. Then Fleisig affixes reflective markers to 15 critical joints, like wrists, elbows and shoulders. Once the hurler is in position on the institute’s pitching mound, Fleisig limits outside light and relies on rings of LED infrared lights positioned at each camera to illuminate the markers.

Reflective markers are attached to 15 joints of pitchers to be evaluated. Photo courtesy of American Sports Medicine Institute.

As the hurler goes through his windup and delivery, the six high-speed CCD cameras capture the dots throughout the pitching motion and send pixel data to a computer. Using a program that relies on direct linear transformation, the computer combines the two dimensional data describing the position of the dots from the six cameras to create an image that correctly shows the position of the dots, and the pitcher’s joints, in 3D space. That information is mapped onto a stick figure that replicates the hurler’s pitching motion so it can be studied to enhance performance and correct flaws that could lead to injury.

Fleisig uses technology from Motion Analysis in Santa Rosa, Calif., to capture motion data but relies on a database of movements he has assembled since pioneering this work in the 1980s to establish a pitching motion baseline for analysis as well.

“For years, we tested baseball pitchers at all levels- kids and adults,” he explained. “We tested healthy pitchers and injured pitchers. We established databases and were peer reviewed by the scientific community. Now that the database is established we’ve put it out there and use it.”

Increasingly, major league teams are turning to the institute to protect and maximize their investment in pitchers. For the past couple of seasons, the Oakland A’s have sent pitchers to Fleisig for analysis. This season, pitchers from the New York Mets and the Cleveland Indians are going to Birmingham as well for analysis.

Has Fleisig’s biomechanics analysis helped the major leaguers? So far, the jury is still out, said Fleisig, because the sample size has been too small. But this year, Fleisig believes it will be easier to make a judgment. “About October is when we’ll see how it played out with the pitchers who came here,” he said.

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