noun - The core relates to the bodily region bounded by the abdominal wall, the pelvis, the lower back and the diaphragm. The main muscles involved include the transversus abdominis, the internal and external obliques, the quadratus lumborum and the diaphragm.
In anatomy, the core refers, in its most general of definitions, to the body minus the legs and arms. Functional movements are highly dependent on the core, and lack of core development can result in a predisposition to injury. The major muscles of the core reside in the area of the belly and the mid and lower back (not the shoulders), and peripherally include the hips, the shoulders and the neck.
Major muscles included are the pelvic floor muscles, transversus abdominis, multifidus, internal and external obliques, rectus abdominis, erector spinae (sacrospinalis) especially the longissimus thoracis, and the diaphragm. Minor core muscles include the latissimus dorsi, gluteus maximus, and trapezius.