[coophitter]

Hey Triad, Thanks for the response, my argument is that the extensor action in a swingset example is not muscular and neither is it in the tetherball example. The extensor action in both cases is a resultant force and not a direct muscular force. I think extensor action exists in golfstrokes, but it is not developed and maintained by a constant isometric triceps muscle force. I didn't think about the weight of the child, very good observation!