HOW: Get set-up standing with a band around your back under your arms, then hold the ends of the band in each hand. To perform the exercise, perform an upper cut punch motion - think about punching forward, up, and diagonally away from your shoulder. As you punch, rotate your hand and arm out as demonstrated in the video so that your palm is facing up, while simultaneous rotating your body in the same direction. Return to starting position, perform on the other side, and repeat.
FEEL: You should feel your shoulder blades and shoulder muscles working in this exercise. You should feel your shoulder blades moving away from one another and ‘wrapping’ around your body towards your armpits.
COMPENSATION: Do not shrug your shoulders, do not arch your back, try to time your arm motion and body rotation accordingly.