Just gonna copy paste, this sums it up
"So what about hitting the different heads of the chest? Can you isolate the clavicular and sternal portions for example? Great question. There are many really smart people who’d say no, that doing a flat bench barbell press, for example, works your entire chest equally. Their logic is sound, but here’s the thing: sometimes we overcomplicate, but we also sometimes oversimplify.
I know that when I do declines on the Smith, flat flyes, and barbell benches, my lower and outer pecs are much more sore the next day than my upper pecs. When I do tons of barbell and dumbbell inclines, my upper chest is very sore the next day, and when I do a lot of machine flyes with a good stretch and flex, my pec fibers by the sternum are extremely tender the next day.
So to me, in this simplistic way, I do believe that varying angles fatigues different portions of the muscle to a greater or lesser degree. I know, nothing groundbreaking there, but many of my colleagues would disagree."[/quote]
Well, that’s kind of a personal approach, and not really a scientific. Many would argue that you while you indeed can isolate the clavicular and sternocostal head, you cannot isolate/emphasize the inner or outer portion of the pecs. Dips, for example, may cause “tenderness” so to speak, but that may, in fact, not be the muscle. Many people have f***ed up their sternums by doing chest dips.
The world is not black and white, and these isolate arguments are based on people that can not see grey. Isolate implies that you completely de-activate the other muscles, and Z-Raws post while not meaning it implies that he(meadows) felt sore in his lower chest so he only worked his lower chest. Both implications are false.
The primary target may have been lower chest and his chest is strong enough that the rest wasn’t sore but it doesn’t mean the other areas did not get trained. So no you can not completely isolate a muscle group, but you can train it with primary targets.
The better you can focus in on that muscle group the more likely you are to have a better MMC and likely better bodybuilder, but even then it’s not 100% thankfully otherwise you would get hurt in a 3d world.
I think you are misinterpreting Zraw/Meadow’s post. He/they are not suggesting that you can completely turn off other muscle groups (you can never do that, unless maybe using electro-stim), simply that different joint angles, lines of pull/force, and force curves will “isolate” (I agree, bad term, a better word might be emphasize or “focus on”) different muscle fibers/areas of the Pec Major muscle. His/theirs is a counter point to the line of thinking that states that you can only activate a muscle or not and EMG tests like the one Dorian cited which suggest that decline bench will better build the clavicular head of the pecs than incline movements.[/quote]
I never said that.
I said statements like the original post start because that is what is implied. I thought I clearly stated it is not the meaning of his statement.
Z-Raws post while not meaning it implies that he(meadows) felt sore in his lower chest
Oops, my mistake. Carry on.