Baseball hitters are chasing more power, and that pursuit appears to be fueling a rise in fractures of a small hand bone called the hamate. NPR’s Ayesha Rascoe spoke with Dallas orthopedic surgeon Dr. Thomas DiLiberti, who has treated dozens of players with hamate injuries, about what the bone is, how it breaks and why it matters.
The hamate sits in the palm near the crease by the wrist, on the side of the small finger. You can feel a bump on the palm toward the wrist; the hamate itself lies about a centimeter farther down and in.
Hamate hook fractures have long occurred in baseball, DiLiberti said, but recent changes in how players grip the bat have increased risk. Batters are holding the bat farther down the handle so the knob sits directly beneath the small-finger side of the palm. That positioning puts the knob over the hamate hook; a sudden torque when the bat hits the ball can press on the hook and snap it off.
After surgery and healing, hitters can still be affected. Tendons to the ring and small fingers wrap around the area where the hamate projects, so a fractured hook changes how tendons glide and can reduce grip tightness. Even a modest drop in grip strength or a small change in swing mechanics—5 to 10 percent—can matter to a professional hitter.
The injury isn’t limited to pros. High school and college players who are big and powerful can suffer the same fractures. DiLiberti said increased awareness—amplified by social media—has led more parents and coaches at the amateur level to pay attention to hamate injuries and their signs.
DiLiberti, a Dallas-based orthopedic surgeon who specializes in hamate injuries, discussed these points with Rascoe ahead of Major League Baseball’s opening day, as several players began the season sidelined with hamate fractures.