[Theodan]

The other interesting thing in Miura's article (by the way, it was in a journal called Sports Engineering), was that his study of better golfers, showed that the club did NOT trace the expected arc at the bottom of the swing. (Not wanting to raise any trouble here!). Instead, the club was pulled inside the expected arc, creating (Miura claimed) a flat spot in the swing. It can thus be assumed, that Miura at least, felt that a pull against the direction of centrifugal force (shortneing of radius?) improved both power (acceleration through impact and therefore compression I guess) and accuracy.

What I find interesting about this is I have stood behind good golfers, and watched them swing with what looked to my eye like an outside to inside action. The only thing was, their supposed 'cut shots' started straight and either stayed straight or drew (they were NOT pull hooks), plus they went far. Could this be the parametric acceleration motion Miura described?

Due to some scar tissue in my left shoulder and tendonitis in my arm, I had a tendency to pull my left arm in quickly to my left side. (Keep in mind this was a left-side-body-drag-the-arms swing at the time). I drove a Master PGA Instructor nuts with the ability to start the ball right of target and draw it in. To me it felt like the ball should just go way right. Even though I was slightly chickenwinging and had lousy follow-through.

Neither of us was the sharpest knife in the drawer when it comes to physics, but we watched it frame-by-frame. The only reason we came up with as to why it didn't totally/immediately kill the speed, was the same reason a spinning iceskater goes faster as they pull their arms in.

Needless to say, it also included a host of malcompensations and timing issues. If a golfer included an intentional radius shortening in their swing repertoire, I would think it would be tough to manage. It totally hosed me until I got it into my head to extend the left arm properly through.

Charlie