I don’t think people mean difference in development, as in one is shriveled and weak, but often differences in flexibility and minor changes in power can affect

I don’t think people mean difference in development, as in one is shriveled and weak, but often differences in flexibility and minor changes in power can affect thing. Consistent poor usage of your body can and does cause certain muscles to compensate for others, an imbalance if you will, because that’s just how the human body moves. A lot of pain I’ve experienced over the years has been caused by an imbalance in flexibility between muscle pairs. Lately I’ve been having issue with the pectoral minor vs. one of the rotator muscles that’s been making overhead pressing a very pinchy experience. Releasing the pec minor with a lacrosse ball has done wonders for improving the comfort (and power) of my overhead press. My only beef with this process is that figuring out which pair is imbalanced is really hard, and I could never do this on my own. It is not intuitive or logical that a pain I'm feeling in my shoulder can be fixed by focusing on my chest.