An employee was observing a packer/hopper assembly that he had just finished when the hydraulic fitting failed and he was struck by the hydraulic hose and sprayed with hydraulic fluid. He then fell backward and struck the back and top of his head on a solid square object located approximately 5 feet behind his observation point. He suffered a small cut to the skin on the right side of his neck, bruising from the cut down across his right clavicle, bruises to the back of his neck, and a scrape to the top of his head.