Final answer:
The intercostals are not considered part of the deep core, which includes muscle groups like the diaphragm, pelvic floor, and abdominal wall muscles. These deep core muscles are essential for stability, breathing, and bodily functions like urination and childbirth.
Step-by-step explanation:
The correct answer to the question is Intercostals, which are not part of the deep core. The deep core muscles typically refer to those that stabilize the torso and include the diaphragm, pelvic floor muscles, and certain muscles of the abdominal wall.
The diaphragm is a dome-shaped sheet of muscle that separates the thoracic cavity from the abdominal cavity and is the primary muscle responsible for breathing. The pelvic floor includes muscles such as the levator ani and the ischiococcygeus, which support the pelvic organs and help in functions such as defecation, urination, and childbirth. The abdominal wall muscles, which include the rectus abdominis, external oblique, internal oblique, and transversus abdominis, all contribute to trunk stability. Meanwhile, the intercostals muscles, including both the internal and external intercostals, aid in respiration by enabling the expansion and constriction of the rib cage, but they are not typically classified as part of the deep core.