I've commented many times that the common 'Twist the head and pop the neck' chiro technique is too aggressive for many with concussion related cervical issues, especially C-1 and C-2. There are chiros who use a gentler technique.

Physical therapists have many degrees. They used to be just bachelor degrees, then master's degrees, now Doctor of Physical Therapy. The only difference is with the DPT they study and may even participate in research. The AMA has pushed for PT's to use science based medicine and the DPT trains for this. It can be a hindrance as some symptoms/disorders do not have any valid research. The best PT's I know can work outside the box and affect real healing by doing so.

The Certified Orthopedic Manual Therapist is partly an attempt to promote a PT based set of chiro skills and protocols. They recognized the subluxations that chiros treat and have tried to develop treatments for them.

DO's have some of the same COMT protocols in their Cranial-Sacral Therapy/Osteopathic Therapy protocols.

The important point is that there are some overlaps of skills and treatments. The patient needs to understand these issues and make choices rather than let a doctor of any flavor keep treating and collecting fees regardless of outcome.