As players swing for more power, a small palm bone called the hamate is being injured more often — and it can take hitters out of the lineup. NPR’s Ayesha Rascoe spoke with Dallas orthopedic surgeon Dr. Thomas DiLiberti, who has treated dozens of baseball players with hamate injuries, about what the bone does, how it breaks and why it matters.
The hamate is a tiny bone on the palm side of the wrist near the crease on the small‑finger side. You can feel a knuckle or bump on the palm toward the wrist; the hamate itself sits about a centimeter deeper and a bit lower from that surface spot. One thin projection of the hamate, called the hook, is particularly vulnerable.
Hook fractures have long occurred in baseball, DiLiberti said, but a recent change in bat grip appears to raise the risk. Many hitters now choke up or place the bat so the knob aligns directly beneath the small‑finger side of the palm. When the knob sits over the hamate hook, a sudden twisting force at ball contact can press on and snap off that projection.
Surgery to remove the broken hook and a period of healing usually restore function, but subtle problems can remain. Tendons that control the ring and small fingers loop around the hamate projection, so losing the hook alters tendon glide and can lessen grip strength. For a professional hitter, even a modest decline — a few percentage points in strength or a small swing‑mechanics change — can be costly.
The injury isn’t confined to major leaguers. Powerful high school and college players can experience the same fractures. Greater awareness, driven in part by social media, means more parents and coaches recognize the signs and seek care sooner.
DiLiberti made these observations in an interview ahead of Major League Baseball’s opening day, at a time when several players were already starting the season sidelined by hamate fractures.