[coophitter]

It is very difficult to discuss this magic right forearm. In my tether ball example and swingset example the thrust applied to both objects may be a little more than 90 degrees to their respective tether lines and then the objects separate from pressure points at 90 degrees. So initial thrust at more than 90
degrees can act as an initial stretching force on the tethers, but by separation this force is no longer acting on the respective tethers.

In a golf swing where you exert a little triceps thrust at address to stretch the left arm tether and then feel that this thrust is still in effect through the backswing and downswing is quite confusing to me because I feel it too, but if there was a true magic right arm thrust down the line of the left arm tether then the left wrist would have no cock at address and wouldn't cock at all during the backswing. Also when the right elbow bends on the backswing and the triceps fibers lengthen, an eccentric force is developed that can apply thrust to slow down an object, but it can't stretch or move the object concentrically, and it can't keep the object the same distance away isometrically. What we are feeling on the backswing is the triceps developing a force that prevents the elbow from bending too quickly and/or too much.

On the downswing we feel the concentric contraction of triceps fibers that straighten the elbow in hitting, but the initial thrust is not down the line of the left arm but quite close to or at 90 degrees against the line of the cocked left hand. True extensor action down the line of the left arm can only occur when the left wrist is uncocked. I'm going to stop now because I'm getting quite confused and need help, but I really think that extensor action as described by kelley is an isometric force wherein triceps fibers would remain the same length during force production. If the elbow bends or straightens, the fibers are not remaining the same length and different forces occur.