You shoot a great game of pool, Fatman I don't know about you, but when I think of strenuous sports, I usually don't think about pool. (That's billiards, not the kind that you swim in.) Today's Google News search for Feldie-related words started with "muscle tonus," which turned up this article from Onthewirebilliards.com about pool players. It was written by a DC. Among other things, it says:
Although the pool cue case only weights approximately 10 pounds, it is enough of a constant tension to cause the upper trapezius muscle to contract and get locked in a state of tonus (constant contraction or spasm).
Who knew?