On 02/19/04, ee reported to supervisor that he had backed the dozer into a small depression causing the dozer to jerk. The ee began to feel pain & numbness in his shoulder & arm. He did not feel he needed medical attention. On 02/26//04 he did go to the company doctor who suggested therepy. This did not help & the ee had surgery on 05/20/04, making it a lost time accident.