Adductor pollicis jamming injuries in the professional baseball player: 2 case reports.

We characterize a mechanism of injury, injury pattern, and treatment algorithm for adductor pollicis myotendinous injuries in 2 professional baseball players. Similar to myotendinous eccentric injuries in other anatomical areas, the adductor pollicis sustains a sudden forceful eccentric load during a jammed swing, resulting in intramuscular strain or tendon rupture. Based on the reported injury mechanism, and magnetic resonance imaging features of these myotendinous injuries, the thumb of the top hand during a jammed swing was suddenly and forcefully eccentrically abducted from a contracted and adducted position, resulting in injury patterns.