AFTER ADJUSTING JAW SETTING, EMPLOYEE REMAINED ON CONVEYOR AND REQUESTED JAW START. JAW BOLT WAS STARTED, EE ROLLED OVER TO AVOID CROSS MEMBER & TWISTED LEFT LEG. EE'S TRAINED IN TAGOUT/LOCKOUT. PORTABLE UNIT NOT LOCKED OUT, OPERATOR TO INSTALL SEPARATE SWITCH BOXES TO PRECLUDE FUTURE OCCURANCE.