EMPLOYEE HAD CLIMBED ON TOP OF A GUARD THAT IS ELEVATED ABOUT 3 - 4 FEET FROM FLOOR LEVEL. WHILE TAKING DOWN A COME-A-LONG, EE SLIPPED OFF THE GUARD. HE LANDED ON HIS FEET, THE COME-A-LONG WAS IN HIS LEFT HAND. THE COME-A-LONG WEIGHT THREW HIS HAND AGAINST THE FRAME OF A MOTOR CATCHING THE HAND BETWEEN THE MOTOR & THE COME-A-LONG.