Can You Swing Well Without It?

By turning the hips a little bit before the shoulders, you're putting additional tension into the core muscles. And because of what's called the force velocity curve, that allows you to actually contract the muscles more forcefully. Muscles can produce more force in an eccentric contraction than they can in a concentric contraction. So if you can eccentrically contract, that is to say, stretch a little bit, then you can provide more power in the down swing and end up with a higher club head velocityin velcity for a less amount of work.