"Unlike the superficial core muscles like the rectus abdominis—what most people refer to as the six-pack—these deeper muscles work more for stabilization than for movement." Stewart says ...

Uptake of technetium-99m methylene diphosphonate by the rectus abdominis muscle was unexpectedly found in a 29 year old man who had started to perform 30 to 40 sit ups a day for five days before the ...