Great short vid on whether your “weak” muscle is actually just tight and off balance. An important and valuable question for anyone who trains. Many of my clients suffered from this mix up. The muscles my clients perceived as weak or actually in fact very tight and off balance. While they were strong, their power couldn’t be utilized fully. Once we corrected the balance issues, and fixed alignment, that muscle typically revealed itself to be quite strong. So strong it usually shocked the crap out of my clients.
So, if you feel tightness, and the amount of weight your pushing doesn’t seem to be going up much, you may be experiencing this very event. Correct alignment first, and stretch that baby out!