I'm trying to work out the science of a simplified model of the human body, and I would appreciate your help on some of the basic formulae.(adsbygoogle = window.adsbygoogle || []).push({});

If I have a bar (representing the shoulders), which has a central pivot point, connected by a unrestricted hinge to a rod (representing the upper arm, connected by another hinge that only has 180 degrees of movement (representing the forearm and the elbow), connected by another hinged joint to a lump representing the fist, what formulae can I use to calculate the effects of:

twisting the "shoulder"

extending the "forearm"

My ultimate goal is to calculate the optimum way to deliver force to the fist in a whipping motion.

How much more complicated does it make it, if I allow the "shoulder" to have rotation around the x axis (simulating a shoulder roll) as well as around the y axis?

Many, many thanks in advance!

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# Pivots and rotational velocity

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