Now in no way shape or form am I gonna get into the debate just wanted to give some info.
Pectorialis Major
Connects to the upper arm and ALL along the sternum.
Now some may have enough muscle control to work parts of that muscle harder such as were it connect to the sternum.
Put your right arm in front of you with your left hand on the pectorial muscle for the right arm. Now first raise your right arm till your elbow is just at or slightly above eye level. Now while keeping your arm straight and the left hand on the pec move your right arm in toward the left till your upper arm is as close to laying across your chest at that angle as possible and flex as hard as you can. Now start over but this time lower your right arm till your hand is just a little above your waist and repeat the flexing movement.
Now when I do this I feel a tighter sensation in the upper chest in the first motion and tighter in the lower for the second one. Now it does flex the entire pectorial muscle, there does seem to be some difference in the degree of tention in the muscle at the different areas of the sternal connections to it.
Like I said not debating or arguing just thought I would put in my two cents.
Pectorialis Major
Connects to the upper arm and ALL along the sternum.
Now some may have enough muscle control to work parts of that muscle harder such as were it connect to the sternum.
Put your right arm in front of you with your left hand on the pectorial muscle for the right arm. Now first raise your right arm till your elbow is just at or slightly above eye level. Now while keeping your arm straight and the left hand on the pec move your right arm in toward the left till your upper arm is as close to laying across your chest at that angle as possible and flex as hard as you can. Now start over but this time lower your right arm till your hand is just a little above your waist and repeat the flexing movement.
Now when I do this I feel a tighter sensation in the upper chest in the first motion and tighter in the lower for the second one. Now it does flex the entire pectorial muscle, there does seem to be some difference in the degree of tention in the muscle at the different areas of the sternal connections to it.
Like I said not debating or arguing just thought I would put in my two cents.