rhouzer

i notice that whe n i do chest exercises (push ups) that i pull my right side of my rib cage down and in while my left side of my rib cage still sticks out as if my external oblique or Serratus Muscles are not in use. I think i am using correct posture so i am not sure how to work those muscles or if i favor my right side (i/m right handed). I notice i tend to flex them and have to force the left side to work. Not sure if i lean a sertane way or pull my shoulders in different ways and it would help to know what would cause it so i could look for it? Maybe twisting ab motions, one arm ush ups, what could i be doing to work those muscle on one side more than the other(external oblique or Serratus Muscles?) .