Can you recommend a pain-relieving pro massage device?

I need something that will relieve muscle spasms causing back pain. There is such a thing, but I don’t have knowledge of a type, brand, or other description. I no longer have access to the one that was used on me. It looked a little bit like an electric vibrating meat tenderizer.

With a little too much exertion, I get intense spasms in the thoracic area that last, typically, for 7 hours. Muscle-relaxant meds do almost nothing, and conventional pain relievers have no effect at all. Ice helps a little; heat makes it worse. An application of a pro-level device can put an end to the spasms in ten minutes.

If you know what I’m talking about, please give me your advice. Thank you.