Abstract: At 10:15 a.m. on August 16, 2018, Employee #1 was lubing the pivot joints on the CAT 745 Haul Truck from the ground level. The employee, wearing gloves, was connecting the end of the high pressure lube line from the service truck onto the extended grease line zerk fitting, positioned over the rear passenger side of the CAT 745 Haul Truck. Upon inserting the lube line onto the zerk fitting, Employee #1 squeezed the handle to dispense grease through the 120 psi line. The extended line with the zerk fitting moved away, allowing the high-pressure lube line to inject grease through the skin of Employee #1's left thumb. The high-pressure injection of grease through the skin and into the underlying tissues of Employee #1's left thumb resulted in hospitalization.