Humeral shaft fractures secondary to throwing.

Twenty-seven male military recruits with humeral shaft fractures that occurred during throwing of a hand grenade were analyzed to determine the causes and contributing factors of this fracture in recreational pitchers. Average patient age was 22 years (range: 19-27 years). Objective criteria included type and fracture site on radiographs. Subjective data such as throwing style, previous pitching experience, and prodromal arm pain were obtained. The recruits' throwing style was deemed faulty. Analysis of the fracture configurations indicated an external rotation mechanism.