Medical Massage definition?

I am getting flooded by brochures and emails by places offering Medical Massage Certification.  Is there a definite hour requirement in certain subjects for such a certification now or are all these places putting together their own "Medical Massage Certification" programs?  Are certain states requiring this for hospital work or is this still in its infancy of development?  This is a path I'd like to pursue, but before I invest my time and money I want to make sure I pick the right courses!