Training the inner core is VERY important if you want to prevent low back issues, pelvic floor problems, s*xual problems, and more... - Many people have an imbalance between their outer core muscles (like the abs) and these inner core muscles because they train their outer core not the inner core. - The bad thing is people usually only become aware of and start training the inner core muscles once they start having issues like above. - An ounce of prevention is worth a pound of cure as they say.

Muscles of the back: Video, Causes, & Meaning | Osmosis

Muscles and muscle tissue