EE trammed the dual head roof bolting machine from No. 6 heading to No. 5 heading. He backed the machine up into No. 5 heading to turn around & take bolter to No. 1 heading. As he was backing up the bolter-cable fell off the back of the bumper. EE attempted to put the cable back on the bumper with the bolter still moving & caught his hand between bolter & coal lying on rib.