I had dual plane so partial under and partial over.upright totally natural.you do get some movement of the implant if you flex your muscles with partials or total unders but varies by person, mine isn’t much.on my back you can tell, bending over you can tell if you feel as the muscle holds back part of the implant so you can tell where the natural boob is and then the implant.i hate this but apparently is a trade off for risks of overs.i don’t know how overs act, probably more naturally I would’ve thought but then you might get rippling etc which would be visible and apparently the implant is felt more as isn’t camouflaged by the muscle
