I said it's perhaps the most important when it comes to benching and shoulder health (not to mention putting up heavy weight), not if you want to isolate the pectorals. If that's your goal, you're simply doing the wrong exercise.
Isolate was the wrong word here. However, bench press is one of the key major muscle exercises for strengthening the muscles of the chest, ie, wide grip to target the pectorals more than the triceps.
And I only thought excessive arching was bad for you while benching. There isn't that much force on the back in the bench press anyways, as the weight of the bar should be resting through your traps to the bench, not through the back to your butt (as so many do, incorrectly) the butt should barely be touching the bench. Or do you mean that the power transfer from the leg drive is dangeoraus when you're benching?
Also, I'm curious, how does arching prevent the abdominals from stabilizing? What about arching when doing RDLs, GMs, DLs, Squats, etc? (not excessive arching, but just "normal" arching, if one can call it that)
I was under the impression that he was overarching (outside of the neutral, normal arch of the back). So if that isn't what he is doing, then I was in the wrong.
Power transfer through the legs is not dangerous so long as the back is either flat or at its natural arch. At the same time, utilizing the legs to press a weight that supposed to be lifted utilizing musculature of the upper body isn't really the goal of the standard (not powerlift) chest press. The legs, more than anything, should provide a base of support in order to prevent rotation of the body about the spinal pivot point and in doing so prevent flattening of the shoulders around the edges of the bench in order to provide similar support.
Excessive arch destabilizes the whole core because it places the frontal core (particularly the stabilizing tranverse abdominus) into a stretch. While the core can still stabilize while stretching, it is not as effective as a stabilizer and can actually give out from exhaustion far more quickly during the course of a set, unlike when the lower back is flat against the bench and the transverse abdominus is activated (properly contracted). As for lifts such as squats, it is much the same. You can better stabilize the core, in particular the back, in general by activating your transverse abdominus and flattening your lower back. Since I cannot find it online, I will try to post a NIKE training video on deep abdominal wall activation later today.
And yes, it is possible to retract your scapulae and tuck the elbows without arching, but it's very unnatural, try it out. I never got the tucking down before I started arching my back more. It's hard to explain over the internet.
I'd have to see it because I'm not grasping what you've described here visually.
Why does just about every author I know of recommend arching your back for benching if it's dangeoraus? And we're not talking random BB.com people but for example Mike Robertson.
Also, by keeping the back flat, do you literary mean flat or with the natrual arch?
A natural arch is sufficient for any lift, but you can better stabilize the lower back by removing as much open space between the lower back and the bench.
I've never read an author that has recommended anything more than the neutral of a back during a lift like the chest press. In particular, several of my texts on athletic training quite specifically state that the arch should not be exaggerated at all. I am somewhat familiar with Mike Robertson's body of work; from what I do know, he has helped to train many collegiate and professional athletes through a powerlifting style of resistance training. However, these athletes are probably some of the most fit individuals just about anywhere from a whole body standpoint.
If Olympic-style powerlifting and similar athletic performance is the goal here then it is a sound method provided there is adequate core support (such as a belt). On the other hand, if we are talking about general resistance training and fitness for strength and muscular hypertrophy, it is probably not a good idea to perform a powerlift that can serriously destabilize the lower back in order to shift pain away from the shoulders. I think he should be a little more concerned as to determining why his shoulders are hurting during a standard chest press before he moves on to a powerlift, whether it be muscluar imbalance at the shoulders or outright injury. I'm not saying that I'm absolutely correct on that view, it's just my take on the situation.
