EE STATED HE WAS LEANING FORWARD WITH KNEES BENT ATTEMPTING TO BREAK WINGNUT LOOSE WITH HAMMER & AS HE PULLED HAMMER UP, HE FELT A STRAIN IN HIS RT. GROIN AREA. HE THOUGHT NOTHING OF IT AT THE TIME. HE WORKED ON CLOSING & OPENING 2 SUCTION VALVES & HAD TO REACH UP FOR THOSE. HE FEELS THE HERNIA WAS DUE TO THE COMBINATION OF THE 2 ACTIONS. NON-OCCUPATIONAL CASE, DETERMINED BY CO.DR.