To pull, yank, or lift someone or something upward or to a higher location or position. A noun or pronoun can be used between "jerk" and "up." I jerked my wounded leg up onto the examination table for the doctor to look at. After searching his pockets for anything dangerous or illegal, the police officers jerked the suspect up off the ground and marched him over to the squad car. Sarah jerked up her head when she heard her name over the loudspeakers.
jerk something up
1. to pull something up quickly. He jerked his belt up tight. He jerked up the zipper to his jacket.
2. to lift up something, such as ears, quickly. The dog jerked its ears up. The dog jerked up its ears when it heard the floor creak. The soldier jerked his binoculars up to try to see the sniper.