To answer your question, yes. The Solar Plexus muscles are the top two
Abdominal muscles. They are located directly below the Sternum. The
reason for the popularity of this target is because, they are the
muscles located directly over the lungs. Also they tend to be the
weakest of the Abdominal muscles. There are actually 8 muscles in the
Abdomin. Why then is it refered to as a "six-pack"? Because the Solar
Plexus gets overlooked by the BodyBuilder who wants to look good.
Historically this target is called the "Mark". It is the second most
important target after the "Button" or chin. By striking a solid blow
to the Mark, one can affect a "body knockout" relativly easy. Some
Boxers have made a career on this KO, ie. Bob Fitzsimmons. The
corkscrew punch is specifically desinged to be a Solar Plexus KO. You
are in effect, emptying their lungs of oxygen. No O2 no fight. I hope
this answers your question. For a good study of this I suggest reading
Ned Beumont's book on historical boxing as a modern Martial Art.
Excellent read.
Beannachtai, Wic