The Arms

Posted: Sat 21:45, 18 Jun 2011

Dariousz,

In your paper describing how the arms work, you mention how they work like nunchakoes. I understand this concept, but need more information on the momentum conservation rule. I am one of those that does not trust the loft of the club, so I try to pick the ball clean off of the ground. I really want to strike the ball first, then the ground, and make a divot in front of the ball. I also need more information on letting the club catch up to the forearms? Please advise.

Thanks,
Mike

Posted: Sun 12:10, 19 Jun 2011

Well, the COAM rule has an application in the swing motion as descriptive physical phenomenon, however, it describes neither utterly nor very correctly what happens in reality because COAM refers only to closed systems (e.g. a skater that is in the process of making pirouettes without taking into account external forces that help her in the pirouette).
A golfer does not anything to conserve since starts from zero then changes the orientation. We may apply the COAM rule only in case of the very downswing, however, we need to assume there is a closed system which is a bit tough since isolating the downswing from external forces acting on a golfer and a club (such as gravity) may be too abstract but serves well to describe the general intention. Same for nunchakoo chain concept to describe lag and similar physical phenomena that happen unintentionally because there is not another way possible.

It is worth adding that the problem with automating arms movements lies in lack of connection with stable element of our physical reality - such as e.g. it is relatively easy to automate legs motion thanks to their direct connection to the ground. One can benefit easily from one's own mass and torques in joints in such a scenario.
Arms are distal limbs of the body as well as legs are but they have to move freely. Moreover, they are too long and too complex to be utterly dependent on main body movement. However, biokinetics tells us that they should be dependent as much as possible if the main goal is accuracy. If the main goal is distance - we can state that more freedom is needed here.

Cheers