Im not a doctor, but Ill offer opinions anyway:
The infra red thing I can buy it works because heat therapy can work for inflammation (I think).
Plausible I guess, with the assumption that a) inflammation is a particular problem associated with your injury, b) the heat transmitted by the infra red is of sufficient power to produce a significant effect, and c) the problem is in a location that can be targeted (ie, if the problem is well below the skin, can infra red transfer heat that deep into the tissue?)
ultrasound? For all I knew she was rubbing a tv remote on my back I didn't feel anything.
Has a Cochrane Review about it.
We did not find any convincing evidence that ultrasound is an effective treatment for low-back pain. There was no high-quality evidence that ultrasound improves pain or quality of life.
We did find some evidence that ultrasound may improve back-related function—the ability of people to use their backs. But those effects were so small they may not make any difference to patients’ lives.
The electric cupping thing felt weird, but I'm not even sure my pain is muscular since it's localised to my spine
Not sure what the electric part is supposed to accomplish or how it works, but cupping is usually BS aimed at "drawing out toxins". edit:
As far as I can see, the electric part is just electrically powered pumps instead of heat to create the suction? If so then still complete BS.
the dry needling they assured me wasn't chinese acupuncture
This is probably correct, in that my understanding is "dry needling" is an amorphous concept with no real definition or standardised form / standard practices. Acupuncture is one type of dry needling, but they can just poke you with needles at their whim and call it dry needling, not necessarily in accordance with chinese acupuncture. That said, "trigger points" strongly correspond to acupuncture points.
At a glance, the heat is the only one that doesnt have immediate warning signs.