HOW: Get a cable set-up anchored between shoulder and waist height. Perform a single arm row by driving your elbow towards your back pocket and letting your elbow bend. However, the entire time you perform this row, keep your shoulder blade squeezed back as best as you can. Understand when your arm is reached out in front of you your shoulder blade is going to come forward a little bit, but resist large movements and focus on keeping it squeezed back.
FEEL: You should feel the muscles around your shoulder blade working as well as behind your shoulder and your biceps.
COMPENSATION: Do not arch your back, do not shrug your shoulders.
