jobo
Grandmaster
but he has included the traps, and they don't keep you up right, , where as the legs which you have excluded do indeed play an important role in keeping us upright, try it with out them its really difficultBy picking a definition and working with it. To me, "core" is the muscles with primary involvement in keeping us upright from the pelvis up (so, not the legs,etc.) to the clavicles (so not the neck). Pecs wouldn't be in there.