Lexi Thompson Swing 2014 - Analysis of Joint Positions and Anatomy
Even the most talented professional golfers do not make 'ideal' swings in terms of how their joints can work best, simply because prior to this no-one has ever thought to consider that aspect.
So, an athlete such as Lexi Thompson can improve too, by positioning, at the top of her backswing, her entire spine (head to tail bone), right shoulder and right thigh closer to the positions of her impact, rather than diametrically opposite of what they are!
For instance, if she needs her spine to be tilted away from target at impact, it should be so at the top of the backswing. If her right shoulder is to be externally rotated at impact it should be so at the top. her right hip should not be so extended backwards at the top, as the 'close-packed' position requires some aggressive repositioning to get it into its desired downswing position.