EMPLOYEE WAS DRIVING A PIN WITH A SLEDGEHAMMER. HE MISSED THE PIN AND THE MOMENTUM OF THE HAMMER CAUSED WHAT WAS THOUGHT TO BE A SHOULDER STRAIN. HE WAS EVALUATED BY A PHYSICIAN, DIAGNOSED WIT H SHOULDER TENDONITIS AND RETURNED TO WORK WITHOUT RESTRICTION. THE INJURY GOT PROGRESSIVELY WORSE AND THE EMPLOYEE HAD SURGERY ON JUNE 29, 01.