The two primary culprits he identified were pitching too much -- either too long in a game or for too much of the year -- and pitching while fatigued.
As a partner of renowned Dr. James Andrews at the American Sports Medicine Institute, Fleisig (who has a Ph.D. in biomedical engineering but is not a medical doctor) is one of the foremost authorities on the Tommy John procedure. He focused largely on risk and prevention in youth baseball, but he also discussed the injury as it relates to college and professional ball.
Occurrences of the surgery, which is the replacement of the ulnar collateral ligament with a tendon from elsewhere in the body, have been climbing rapidly in the past 20 years. Both 2012 and '14 saw spikes, and Fleisig said that approximately 16 percent of all professional pitchers have undergone the procedure.
One rather encouraging point that Fleisig made was that pitchers who have come back from the surgery look perfectly typical. A study of Minor League pitchers who had returned to professional pitching after the surgery showed them to be hard to discern from pitchers who had never suffered the UCL injury.
"Once they make it back, they have the typical flexibility and typical mechanics," Fleisig said. "So they're back to normal. This is really good.
"It means that when it works, it works. You make it back, you're back to normal."
Even so, he made it abundantly clear that the best thing is to avoid needing the surgery in the first place. And he presented some striking data to show how baseball can begin to help make that happen.
Citing a study of youth pitchers over an extended period of time, he said that youth pitchers who had pitched 80 or more pitches in a game were four times more likely to have had the surgery. Those who pitched more than eight months of the year were five times more likely.
Yet those paled in comparison to the big one: youth pitchers who said that they had "often pitched" when fatigued were a staggering 36 times more likely to have needed surgery.
"Of all my studies I've done," Fleising said, "this is the biggest result I've found."
Matthew Leach is an editor and reporter for MLB.com. Read his blog, Obviously, You're Not a Golfer and follow him on Twitter at @MatthewHLeach. This story was not subject to the approval of Major League Baseball or its clubs.