Yes. We talk about the rear shoulder "working under" the front shoulder. I like to ask kids if they pop up in a game what is the first thing their coach/dad says to them? It's usually "don't drop your back shoulder". I often then show them a Kris Bryant clip. He's a clear example of the back shoulder working under.
IMO most kids are "two legged" and their shoulders stay relatively level. Spinal axis. When teaching them to work the right shoulder under the left it is important for them to be "one legged" or then they will just be simply dropping their shoulder and prone to popping up. One leggedness allows the hitter to tilt properly and get to all pitches......
Very good post [MENTION=10061]Spartans21[/MENTION]. I do find it interesting how different people can use the same terms to mean different things. That was very confusing for me when I first started following the various hitting sites.