I'm a chiropractor and no, you wouldn't tip the chiropractor or the massage therapist. I think most massage therapists are working for themselves, not "for" the chiropractor. The clients pay them and then they pay their rent and other expenses.
In any case, it's a therapeutic massage by a registered massage therapist in a medical setting, so you wouldn't tip.
I'm told it's different if you have a relaxation massage at a spa or something, or have a massage therapist come to your hotel room. Then you tip.
Nobody's ever tried to tip at our office, although some people have brought in chocolate, baked goods, and other tokens of appreciation. We love that, and especially the thought that someone appreciated our service enough to think of that. But I would never expect it. I'm just happy if they pay their bills on time.