Massage too deep?

It seems that Emilie pressed too hard, or something, in massaging me yesterday evening: a spot on my chest, and one on my left arm, feel bruised, both in places which that would explain. If it was just the arm, it might be any number of things—it's easy to bang one's arm against something and not remember it. That spot on my sternum, between my breasts, no.

OK, that's one not to repeat next week. The odd thing is, she's done similar massage for my elbow before, without bruising my arm, so the problem is almost certainly how much/how hard, rather than where. (The other thing is that the chest massage doesn't seem to have helped; it's possible a lighter touch might, I told her to do it firmly to avoid the risk of tickling.)