Atlas Orthogonal is under the umbrella of upper cervical care. It is one of the techniques that align the occiput , atlas and axis. In my humble opinion, it is one of the best techniques to realign the three rings of the upper cervical region. Dr. Roy Sweat developed the technique. He designed the instrument that helped take out the chiropractor's skill of doing a hand alignment as far as reproducing the angles and the force of the thrust. There are several other chiropractic techniques that address the area but the Atlas Orthogonal is the one I recommend. and have done for over 30 years.
