Driver took load 2 Quarry hit bump, hit head on the roof. Adjusted seat max height. Hit brakes; Shoulder hit steering wheel-pain neck&left shoulder. Stated speed~5mph. Pain in right arm also. Taken to Clinic-Xrays & medications. Lift restrictions. Steering wheel flat&no tilt. Tried to simulate. Was suspect & 8/15 WC determined head & neck would be covered not shoulder.