Final answer:
The nurse's next action should be to logroll the client toward the right side using one aligned movement.
Step-by-step explanation:
When a client with a back injury asks to be moved into the right side-lying position from the left side-lying position, the nurse's next action should be to logroll the client toward the right side using one aligned movement. Logrolling is a technique used to keep the client's spine aligned and protected while moving them from one side to another. It involves a coordinated effort by the nurse and other healthcare professionals to ensure the client's safety and prevent further injury.