Would you need special licenses or certificates to treat certain kinds of people at a day spa?

I'm doing a business plan for a class, and in my market segmentation, I put that I would like to target those who have sustained some type of injuries, with permission for a physician. This would also include runners, bicyclists, college athletes,etc. as well as those that have high blood pressure. Hence, in my rough draft my teacher asked if I would need some kind of license to treat some of my targeted customers. A link would also be helpful to do further research.Would you need special licenses or certificates to treat certain kinds of people at a day spa?
You had me going for a second or two, and then you added the high pretension. This changed things as now you are going to render medical attention in doing so you really should have a either or both on staff. As a Certified Medical Assistant there are number of procedures that you can do but a better bang for the buck would be to hire a LVN, (or LPN in some states) License Vocational Nurse. You should also have a certified and licensed Physical Therapist. Finely nothing should be done on a patient with out a written Doctor's order, If you do you might find yourself charged with quackery.