Major League Baseball’s opening day saw several players sidelined by a spike in fractures to a small palm bone called the hamate. NPR’s Ayesha Rascoe spoke with Dallas orthopedic surgeon Dr. Thomas DiLiberti, who has treated dozens of these injuries, to explain why they’re occurring and what they mean for hitters.
The hamate sits in the palm near the base of the small finger; its hooked projection is about a centimeter down and in from the wrist crease. Players are breaking the hamate hook more often because many have shifted their grip farther down the bat. As hitters place their hands lower—sometimes wrapping the small finger over the bat’s butt—the bat’s knob can line up directly over the hamate. When a swing produces unusual torque or impact, that knob can press on or snap off the hamate hook.
A fractured hamate can affect grip and tendon function. Tendons to the ring and small fingers run around the hamate projection; when the hook is broken, those tendons may rub over the injured area, reducing grip strength or altering how a player holds and swings the bat. Even modest changes in grip or swing—on the order of a few percentage points—can matter at the professional level.
DiLiberti says hamate fractures are not limited to pros: big, powerful high school and college players also sustain them, and spring training has produced many recent cases. The injury and its treatment are getting more attention from parents and coaches as social media spreads awareness; surgeons still perform operations to address these fractures when needed.