THE INJURED WORKER AND OTHERS WERE PUTTING A LARGE TARP OVER A RAILCAR AS RAIN BEGAN TO FALL. THERE WERE STRONG BLUSTERY WINDS THAT LIFTED AND JERKED THE TARP VIOLENTLY. THE EE TRIED TO HOLD T HE TARP DOWN BUT IT PULLED HIS ARM UPWARD AND SPRAINED THE RIGHT SHOULDER BEFORE HE LET GO OF THE TARP. THE DR PUT HIM AN RESTRICTED DUTY AND MEDICATIONS.