Apologies to drill sergeants everywhere but “Stomach in! Chest out! Shoulders back” sucks. While this particular posture makes a soldier appear leaner and meaner on the parade ground, it reduces his ability to function efficiently. Unfortunately, this concept has seeped into general society and has long been accepted as a guide for good posture.
“Stomach in” pushes the abdomen in and up and restricts the movement of your diaphragm (your most valuable breathing muscle). “Chest out” pushes your breathing up from the wide elastic lower lungs into the narrow restricted upper rib cage. “Shoulders back” pressures your throat, vocal chords and neck arteries. Also a rigid ribcage locks down the intercostal muscles between your ribs.
Good posture results in spending the MINIMUM energy to produce MAXIMUM fuel with less overall wear and tear. It appears that a Masai warrior can walk forever and spring into action at an instant’s notice. No military-style posture there. The same could be said for martial arts masters.
Stand and move while gently reaching upward with the center top of your head as if your head could float above your spine. Relax your jaws and shoulders. Keep your elbows in line with your side seams and unlock your knees. Relax your tummy and breathe deep, low, and slow. Now you are ready.
Be well. Breathe beautifully.