Knees are bent and kept that way through to keep the lower back straight. Back is horizontal to the floor.Pull with your elbows.. lift keeping your elbows close to your ribs, the bar is at it's peak when it touches your sternum especially to the point where your abs meets your chest), open your chest and pinch your shoulder blades and hold it for a second or so to feel the back burn a bit. Return to floor.Don't shrug it, this isn't a shoulder exercise. Keep back position static.