When it comes to workout routines, most people tend to focus on muscle groups that they can see or feel working immediately-legs, butt, abs, and arms. Smaller muscle groups, on the other hand, tend to be an afterthought.
Take your shoulders, for example. While you might think about working the visible muscles, the deltoids, it’s less likely you spend time in the gym thinking about how to do exercises that work the smaller muscles that stabilize your shoulder joint, Noam Tamir, C.S.C.S., founder of TS Fitness in New York City, tells SELF.
Source: Self