Lumbrical Tear in Major League Baseball Player Throwing 4-Seam Fastballs: A Case Report.

We present the case of a major league pitcher with persistent finger pain, loss of pitch control, and loss of pitch velocity after an injury during a game. This pitcher only throws fastballs and prefers to only use a 4-seam technique. On examination of the affected hand, it is found that he had tenderness along the palmar iinterosseous near the base of the third metacarpal and no tenderness along the distribution of the flexor digitorum profundus (FDP) tendon. The patient had full range of motion of the third digit. Magnetic resonance imaging revealed partial thickness tears of the second and third lumbricals. Proposed injury was secondary to the 4-seam fastball technique, which pulls apart the FDP of the second and third digit, as well as the FDP of third and fourth digit. This increases the distance between the origins of the second and third lumbricals, leading to strain and tearing. The increased pitch count of the player also may have contributed to the injury. After rest and gradual tossing program, the pitcher was able to return to a preinjury level of function at 6 weeks. One year out from injury, the patient continued to pitch and remained pain free.