To perform a TRX pull targeting the back muscles effectively, start by adjusting the TRX straps to a height where your arms can fully extend while holding onto the handles. Stand facing the anchor point, leaning back slightly with your arms extended in front of you, palms facing each other. Engage your back muscles as you pull your chest towards the handles, squeezing your shoulder blades together, then slowly return to the starting position with control. Focus on maintaining a straight line from your head to your heels throughout the movement to ensure proper engagement of the back muscles and avoid overarching or rounding of the spine.