Muscle growth and strength is always limited by how well you can engage your target muscles. Engaging your chest, arms, shoulders, back and every other muscle in your upper body is heavily dependent upon your scapular alignment.
This exercise is one of the best ways to condition your back muscles how to “set” or tuck your shoulders. If you can get into the habit of setting your shoulders during your workouts you’ll basically be hitting the ON switch for whatever muscles you’re trying to work.
As an added bonus, you’ll also remove loads of stress away from your shoulder joints, lower back and other sensitive areas.
Seriously, practice it for 1 week and I promise you’ll wonder how you were ever able to workout, let alone live, without it.