What is the classic mechanism of injury for the most common carpal bone fracture?

• A. Fall onto a flexed wrist
• B. Fall on a rotated wrist
• C. Fall onto an outstretched hand
• D. Direct trauma to palm

Answer: (C)

FOOSH—fall onto an outstretched hand—is the classic mechanism that causes a fracture of the scaphoid, the most commonly injured carpal bone. When the wrist is extended and a force travels up through the radius, the scaphoid bears much of the load and is especially prone to fracture, often at the proximal pole. This pattern explains why patients typically have tenderness in the anatomic snuffbox and may initially show subtle findings on X-rays. Understanding this mechanism also highlights why direct palm trauma or falls on a flexed or rotated wrist are less characteristic for this common injury.