Unless you’re one of those fortunate individuals born with the Angus genes, pectoralis development has probably been a challenge. Well no more, according to the folks at Body Recomposition. They point out that you, and just about everyone else, has been doing the Bench Press wrong.
To understand what I’m going to describe, you need to understand what the pecs actually do. While they have several other minor functions, their primary function is to pull the upper arm (the humerus) across the body towards the midline. That’s what cable crossovers, flyes or the pec deck train. For the technically minded, this is called adduction (in this case it’s actually called horizontal adduction but I’ll spare you the distinction). Adduction means bringing something towards the midline of the body.
Now, when you bench press, if you actually watch the upper arm, it is pulled across the body. Just like on the pec deck, flyes, etc. The difference is what’s going on at the elbow which is bending and extending. This is most of what screws people up.
You can check out the full article here, and happy benching!