External Rotation Build Muscle?

Does external rotation exercise build any appreciable muscle mass?

I feel like trainers try to sneak them in on people like a mother trying to get her kid to eat peas. They are good for you as far as injury prevention, but aren’t really going to build you muscle in a direct sense (though strengthening your over head pressing does).

However, after incorporating external rotation for a few months, my shoulders feel alot more solid, especially toward the rear. Am I building those tiny ERs or is it just improving my shoulder movemnets?

it has the same synergists as a lateral raise, so it will build your lat deltoids.

Sure it will build muscle it uses muscle Juts not huge ones but yes your shoulders could/should get fuller from them.

Then like you elluded to the will build muscle in a secondary function by keeping you healthy better balanced allowing larger loads and a longer pain free lifting life. Better yet.