Ok, before I ask this question, I know im over-analyzing this, and I know at my level, every muscle is weak. But im interested in this anyways. So if you dont have anything to offer, please hit the back button, otherwise please share your opinions.
So, in a given lift, there is generally a muscle group that you prefer to be dominant. This may be debatable, but lets say for bench, that you want the triceps to be dominant, then the shoulders, and then chest. This may or may not be optimal, but in theory, it is safer, because the triceps are more resilient than the shoulders, than the chest. And order in which these muscles contribute to the lift is in part related to biomechanics (form/technique) and partially due to neurology.
Ok, so lets say you are benching, with a fairly narrow grip, elbows tucked, and bar in a somewhat straight path over the lower chest. This should put bar/joints in positions in which the triceps>shoulders>chest contribution would occur. But the factor of weak/strong muscles may play a part as well.
1)So say im benching, and my shoulders are always fatiguing first. This could mean two things IMO.
a- my shoulders are being recruited too much and are becoming the prime mover
b- my shoulders are weak or have low work capacity and thus are fatiguing.
Which one is it likely? Or how do you figure out which one it is?
2) If your muscles are not recruiting how it is theorized optimal triceps>shoulders>chest, and you just continue to train the main movement BENCH and strengthen everything. Wouldn't it be likely that this flawed pattern will continue, and only hold you back in the long run?
3)Or do you think it will correct itself over time?
4) Lastly, ive seen that in recently Dave Tate switched from training more just focusing on movements, to more of a mind-muscle connection type thing.
Is this just completely bb'ing related or useful at all to a powerlifter.
My last part to this isn't actually a question, but just some random thoughts.
If you are deadlifting or squatting, and your back is always fattiguing and getting sore, then often people will asume they have a muscle imbalance or are doing something wrong. They may just strengthen their back, but often times will focus on strengthening their legs and activating their glutes more by focusing on completing the lift with their glutes. It could be that the back is over-active, or it could just be that its weak. But with "lazy" glutes strengthening your back will only take you so far in strength before you stall or worse get hurt.
Another example, is pulling movements. Some people will do pullups and will feel it almost entirely in their biceps, while others will feel it almost entirely in their back. I have found that going very wide on rows or pullups and focusing on my back allows me to shift the emphasis to my back. But ideally it seems that you'd get as much from both muscle groups as possible. If you are mainly getting just biceps or back on pulling movements, it seems as if this recruitment pattern will only get more ingrained as you train, and your progress will halt.
Lastly, people often say, just bench more. But it seems that when you are more of a beginner you would likely want to correct these recruitment patterns early. Then when you become more advanced you can really focus on your main lifts like bench and this will strengthen all the muscles in the desired order.
Just some random thoughts.