Is there any difference between Emsculpt vs Emslim & can I use it for back pain management?

Wondering if there’s any difference between emaculp and emslim other than the costs? I’m also i t’ possible to ask a practitioner to use it on your middle or upper back for pain management I have weak muscles in that area and would love to try this to strengthen the muscles between my shoulder blades, but not sure the paddles can do that?