I think what you mean is the pectoralis muscle. Yes, so after the implant is placed in, even if you do a dual-plane where you cut some of the pectoralis fibres, the muscle is still functioning. There will be no change in the function of the muscle.
You’re just removing or cutting just a short segment of that muscle. But what is also true is that because the implant is placed underneath the muscle, so sometimes when you move that muscle, there could be some animation effects. It means that the implant will actually shift a bit.