Requirements vary between countries. In the U.S. chiropractors obtain a first professional degree in the field of chiropractic.[164] Chiropractic education in the U.S. have been criticized for failing to meet generally accepted standards of evidence-based medicine.[165] The curriculum content of North American chiropractic and medical colleges with regard to basic and clinical sciences has been more similar than not, both in the kinds of subjects offered and in the time assigned to each subject.[166] Accredited chiropractic programs in the U.S. require that applicants have 90 semester hours of undergraduate education with a grade point average of at least 3.0 on a 4.0 scale. Many programs require at least three years of undergraduate education, and more are requiring a bachelor's degree.[167] Canada requires a minimum three years of undergraduate education for applicants, and at least 4200 instructional hours (or the equivalent) of full‐time chiropractic education for matriculation through an accredited chiropractic program.[168] Graduates of the Canadian Memorial Chiropractic College (CMCC) are formally recognized to have at least 7–8 years of university level education.[169][170] The World Health Organization (WHO) guidelines suggest three major full-time educational paths culminating in either a DC, DCM, BSc, or MSc degree. Besides the full-time paths, they also suggest a conversion program for people with other health care education and limited training programs for regions where no legislation governs chiropractic.[46]
Chiropractors use hands-on spinal manipulation and other alternative treatments, the theory being that proper alignment of the body's musculoskeletal structure, particularly the spine, will enable the body to heal itself without surgery or medication. Manipulation is used to restore mobility to joints restricted by tissue injury caused by a traumatic event, such as falling, or repetitive stress, such as sitting without proper back support.