José Berríos' elbow surgery reminds baseball fans of a troubling reality: the sport's fastest arms often suffer the most devastating injuries. But researchers at the University of Waterloo have discovered something that changes the conversation entirely—pitchers don't need to throw softer to protect themselves. They need to throw smarter.
A team led by graduate student Cedric Attias built a digital skeleton complete with muscles, ligaments, and joints to examine what happens inside a pitcher's elbow during the explosive delivery that produces a 93-mph fastball, the MLB average. What they found could reshape how the sport thinks about injury prevention. Using computer modeling and biomechanical simulation, they identified two mechanical factors that place the greatest stress on the ulnar collateral ligament, or UCL—the small, vulnerable band of tissue on the inside of the elbow that holds it together. A high arm slot and tilting the torso away from the pitching arm during ball release are the primary culprits.
The UCL has a particularly cruel anatomy: it's small, has poor blood supply, and evolution never designed it for the extreme, repetitive forces of professional baseball. When it tears—and it does, repeatedly—pitchers face Tommy John surgery and a grueling rehabilitation process. Some never recover enough to pitch at elite levels again.
Attias, now working as a biomechanist for the Seattle Mariners, made a striking discovery when he examined the model's results. The pitching delivery that minimizes elbow stress and produces the lowest speeds looked nearly identical to the mechanics of Toronto Blue Jays pitcher Tyler Rogers, known for his extreme submarine style—a technique that, counterintuitively, protects the arm even at high speeds. At the opposite extreme, the model suggested that someone throwing 110 mph—far faster than any human has ever thrown—would need mechanics more resembling a cricket bowler: massive trunk tilt and an almost vertical arm angle.
The implication is profound. "One pitcher throwing 93 miles an hour with controlled, upright mechanics puts meaningfully less stress on the UCL than someone using a more extreme technique to reach the same speed," Attias explained. The research, published in the journal Multibody System Dynamics, is the first of its kind to use this level of biomechanical modeling to predict pitching injury risk.
The findings matter beyond the majors. Attias and his supervisor, Dr. John McPhee of the Motion Research Group at Waterloo, envision these insights being used to teach safer mechanics to young pitchers before bad habits—and injuries—take hold. Youth baseball has seen its own rising tide of elbow injuries as young arms throw harder and more frequently than ever before.
The study's central message is refreshingly simple, yet powerful: mechanics matters tremendously. The University of Waterloo researchers didn't discover a way to eliminate elbow stress—that's impossible in baseball. But they've shown that pitchers can maintain professional velocity while meaningfully reducing injury risk through controlled adjustments to arm slot, torso positioning, and lower body movements. In a sport where careers end and young athletes' dreams fade with a single ligament tear, that's not just progress. That's hope.