It’s a concept of how we should position our shoulder when doing any sort of lifting with our arms. Now some will say that this is ridiculous – we just move our arms and that’s how they should move. I could get behind that line of thinking. Except for one thing: many of the people that come and train with me don’t actually position their shoulder properly when moving their arms, and then they complain of pain or discomfort in their shoulder or neck when doing exercises like pushups, rows, and planks. But when I help them to position their shoulder properly, they proceed to exercise without pain or discomfort.