The back of the neck nobody trains. Until now.
Keep it slow and controlled. Light load only, the neck is no place for ego.
Face down with your head off the bench, lifting your head back and up works the extensors along the back of your neck, the muscles that hold your head up all day and stabilise it under load. Starting with the chin dropped means each rep travels through a genuine stretch before the squeeze at the top. It is the pull to the neck curl's push, and most people need it more, given how much of modern life is spent looking down.
Shrugs move your shoulder blades and train the traps, this moves only your head and trains the deep extensors at the back of the neck. Big traps do not automatically mean a strong neck, the two work together but are not the same exercise.
To level with your spine or a touch beyond, no further. Cranking into a full backward tilt compresses the joints without adding useful work. A smooth arc from chin-down to head-level is the money range.
Strengthening the back of the neck is a sensible piece of the puzzle if hours of screens leave you achy, alongside breaks and better positioning. It builds endurance in exactly the muscles that fatigue when your head hangs forward.
