A nurse is preparing to lift a client up in bed. Which of the following should the nurse do to help avoid injuring his back?

Number 3 is correct.

Rationale: Engaging the core (stomach) and leg muscles provides the safest traction for moving a client in bed. Feet should be shoulder width apart. The client should be instructed to help as much as possible. The head of the bed should be flat, if the client can tolerate it.