I live in Australia so the terms and names may be different. I trained in the modality of kinesiology and kinergetics. "Touch for Health" was the course that is undertaken to learn basic kinesiology. Kinergetics utilizes muscle testing but introduces energetic healing (reiki, theta energy) for balancing. Both modalities have specialisation courses as well. I believe practitions of both are now located world wide.
The main premise is that the body has an intelligence of its own, and it reaches outside of the body. It bypasses your conscious brain. You can muscle test for anything you can think of. For instance, you might love bread, broccolli, whatever, but when you muscle test whether the body "likes" it, the muscle will go weak. You have developed an allergy or sensitivity to that food or food group. You can muscle test for where a particular fear or "phobia" came from through age recgression (and of course, also get into past lives, or genetic famial cellular memories, etc). Quite often, just the knowledge coming forth is a healing in itself, but you do energetically balance chakras, organs and glands, often utilising crystals, essential oils etc. It is quite fascinating.
I then went on to learn Theta Healing. Now this IS amazing. Almost instantaneous. Utilising muscle testing, but then working with the creator.
Hope this helps