lets use bench press as an example for my question:
We all know that the body favors the dominant muscle most in movements that utilize it, so say your bench pressing and your triceps is the strongest, would that not mean that your triceps would get a higher EMG score than say a guy with a dominant chest?
so does this mean that the EMG score is useless in compound exercise but viable in isolations?
I was reading around about this, and I found somewhere in the forums when a similar question was posed regarding the difference in leverage a shorter guy has than a taller guy that he actually used 4 guys of varyint height/porportions when doing these tests, and the results were generally the same for everyone of those people. I think it is unlikely that Contreras would have had 4 "triceps benchers" as that I feel would be rare and he should know better. Hope this is an adequate answer.
Something I was always wondering about is when I saw that the parallel squat had the highest gastroc activation. I kept reading for some explanation but it was never talked about lol. Is this some kind of calf exercise that is different than what it sounds like??? Never had sore calves from squats
Yea, it may not be necessary to know inorder to get 'big and strong' but some people are actually interested in knowing this sorta stuff. I'm sure you have a few interests or hobbies that are not shared by others so please respect the fact that it is interesting to some.
Just for the sake of spitballing...Is it possible that it is some type of static contraction, like a plyometric exercise (at least I know I havnt really ever heard of anyone getting huge on that type of stuff)? Perhaps due to the fact that they serve to aid in balancing the movement, your body sends signals that would keep that part of the body active and therefore since it is engaged in balancing it is highly active. Balance is a very nerve based event, however not always involving hard contractions that would result in the type of activation and therefore growth that would be desired on say a bodybuilding forum.
The data shows that the parallel squat has the highest 'peak' activation of the gastroc but the lowest 'mean' activation out of the bunch. From what I understand, this means that at some point during the exercise the gastroc was under very high tension but not for the ideal time required to produce and significant hypertrophy (as evidenced by the fact that no one does squats specifically for calf development). Also, as mentioned above there are variables that we all wonder about such as - "did he come forward on the squat and therefor have to engage the calf more than usual to keep himself upright?"... who knows.
Evaluation of raw EMG signals for comparison between muscles or individuals is next to useless owing to different spatial filtering that happens owing to different anthropometrics (body fat levels, orientation of electrodes to muscle fibers).
Unless the signal is normalized, and you compare apples to apples (concentric to concentric and don't compare concentric to eccentric) EMG signals are irrelevant.
To determine whether someone was a chest or tricep dominant lifter, you would need to collect maximal concentric activity during a 1RM for each muscle (whatever elicits the most activity, not necessarily a bench press just whatever has the highest mV reading), then normalize the activity collected during a bench press to that activity. This would give you a % of maximal activity, which would then allow a relative comparison between muscles and individuals.
Bret's work is cute but not appropriate application of scientific method.
Contrary to several comments above, this type of assessment could be invaluable, especially when combined with technique analysis, for choosing what type of exercise or technique modification would work best for an individual.
I know some biomechanics researchers at my uni use EMG as one of their standard tools. Always wanted to play around with it a bit...
As for Bret's work, while I agree that he did not perform a strict scientific study and given the tiny scale and, most likely, less than strict setup, the errors are probably quite significant, it still seems like something worth thinking about. I'm not obviously suggesting that everyone suddenly starts running EMG tests to figure out their best exercises (especially since factors other than activation would be meaningful), but it would be interesting to see the results of a proper study, ideally performed on multiple populations, for example with different body proportions and training histories.
I would imagine most (if not all) really big guys figure all this out by themselves, simply by trying exercises until they find the ones that work for them. Just one of the reasons why no two pros train exactly alike. No reason not to compare those "in the trenches" results to relevant scientific work.
On the other hand I am a big geek and I get almost as much pleasure from reading about all this as I get from figuring out how to do all this "in the field".