Doctors of chiropractic must complete two to four years pre-med curriculum and four to five years at an accredited chiropractic college. The complete curriculum includes a minimum of 4,200 hours of classroom, laboratory and clinical experience. Approximately 555 hours are devoted to learning about adjustive techniques and spinal analysis in colleges of chiropractic. In medical schools, training to become proficient in manipulation is generally not required or offered to students.