Reset rounded shoulders against the wall.
Keep your lower back flat to the wall, don't let your ribs flare.
Wall slides restore the overhead motion that rounded shoulders slowly steal. With your back, hips and head against the wall, sliding the arms from a goalpost to overhead forces the shoulders to move while the ribs stay down and the lower back stays flat, which is exactly the control most people are missing. It works as shoulder prep before pressing days and as a daily reset for anyone who spends hours at a desk.
It just means you have found the exact restriction the drill exists to fix. Only slide as high as you can while keeping contact, and the range will improve session by session.
Your ribs are flaring to fake the overhead range your shoulders do not have yet. Reset with your lower back flat, exhale, and accept a smaller slide until the mobility is real.
Little and often works best. A short set before upper-body sessions and on desk-heavy days will do more for your overhead position than one long session a week.
