EE HAD REMOVED ALL MOUNTING BOLTS IN MOUNTING FLANGED ON HEADER ASSEMBLY. EE HAD TURNED HIS BACK WHEN UNSUPPORTED HEAD ASSEMBLY FELL OFF VACUUM PUMP STRIKING EE. EE WAS KNOCKED TO THE GROUND H URTING HIS LEFT SHOULDER, UPPER BACK/NECK AREA, HEAD & RIGHT LEG. EE WAS GIVEN MUSCLE RELAXERS & HAS STARTED PHYSICAL THERAPY.