Chiropractic was founded in 1895, in the USA, by Daniel David Palmer but it is now a much more diverse therapy than its origins.
It is based upon the understanding that good health is dependent upon a normally functioning nervous system, especially the spine and nerves extending from the spine to all parts of the body.
Chiropractic Doctors or Chiropractors, may sometimes refer to a patient's subluxation, which is a misalignment of the spine that interferes with nerve signals transmitted by the brain.
This is great for / symptom indicators:
Arthritis and joint pain
Lower blood pressure