For this exercise, you should be sitting, or standing, with your back straight. Maintain good posture throughout this exercise.
In this exercise, imagine that you are trying to hold a pencil between your two shoulder blades. You can only hold it there by squeezing your shoulder blades together.
Actively focus on your shoulder blades inching or closing into the middle, preferably with a slight depression or downward focus.
Try to avoid having your shoulder blades rise in an upwards direction.
Avoid letting your arms move the shoulder blades, dictating the pattern. Instead, your shoulder blades should be activated by the muscles in your lower back.
Hold this position for five to ten seconds and then, slowly release. Repeat 20 times/session for 2-3 sessions/day.