It is very commonplace to hear osteopathic manual medicine be equated with chiropractic medicine. While I cannot attest to what the principles of chiropratic medicine are, I can share some insight as to how OMM may differ.
Osteopathic physicians are trained in both traditional medicine and in manual medicine, allowing them to treat not only disorders of the neuromusculoskeletal system but every other body system as well. What is often misunderstood about OMM is that it isn't just effective at treating a sore neck or an overworked vertebral column. Patients with COPD, GI disease, and other such internal processes respond to intervention with manual medicine.
Osteopaths are trained not only to evaluate the bony skeleton, but are also taught "layer palpation" which enables them to differentiate bone from tendon from muscle from fascia, and so on. We use a lot of soft tissue techniques in order to correct areas that appear to be malaligned or are causing pathology for the patient. This should not be confused with massage because there are methods of diagnosis that must precede the treatment.
Lastly (although there is much more to be said), the concept of holism in osteopathy is most prevalent in the teaching of OMM. This art teaches you how to conceive of the body as a functioning whole, that pathology in one area affects all of the other systems because they are interrelated, even your psyche.
It is difficult for me to say whether or not treatment by both a DC and a DO would be beneficial. I think that the extensive medical background of the DO provides the most complete care but due to lack of knowledge about the profession, it does not receive the attention that it deserves and most people turn to chiropractic medicine first. I would suggest talking with a DO who practices OMM regularly and a DC to see what their views on the subject are. I'm sure a lot of it depends on personal preference and chief complaint from the patient.
I hope this has been helpful for you!
Take care,
Julia
MSUCOM MS-II