Strong Fitness Bodybuilding Girl With Abdominal Six-pack Belly Muscles

It is contained in the rectus sheath.
The rectus is usually crossed by three fibrous bands linked by the tendinous inscriptions. While the "sixpack" is by far the most common configuration of the muscle bellies of the rectus, there exist rare anatomic variations which result in the appearance of eight ("eightpack"), ten, or asymmetrically arranged segments. All these variations are functionally equivalent.
• Function xdot
The rectus abdominis is an important postural muscle. It is responsible for flexing the lumbar spine, as when doing a "crunch". The rectus abdominis assists with breathing and plays an important role in respiration in the event the patient is short of breath. It also helps in keeping the internal organs intact and in creating intra-abdominal pressure, such as when exercising or lifting heavy weights, during forceful defecation or parturition (childbirth).