[cyberferret]

Well, when you consider that even Tiger Woods had to take an extended break from golf and completely redesign his swing to prevent permanent shoulder and back problems, it doesn't seem to be a 'genetic' thing per se, but rather a human mechanics limitation.

Some sporting activities are just outside the scope of design of our bodies, it would seem. Much like trying to use a Japanese chef knife to prise open jar lids. It will work up to a point, but not being the core design of the tool, you are guaranteed of breaking the knife at some point, or at least severely damaging it.

It would appear that the human frame is not suited to short, explosive, twisting action of the arms and shoulders while the lower body remains planted.