A chiropractor is not a recognised medical professional and so may not be the ideal first contact to assess your back problems. I would recommend seeing your family doctor or a specialist (orthopaedic surgeon or neurosurgeon) to assess your back problems before you proceed to ancillary treatments.
To become orthopaedic surgeons or neurosurgeons, after graduation from medical school, all doctors aspiring to be surgeons start their life as house-officers. Following which, they become medical officers and if found suitable, will enter surgical training programme either as orthopaedic or neurosurgical trainees (or residents).
They will then complete the required training of several years including rotation through different specialties and disciplines before they are eligible to take their exit examinations and qualify as specialists. This training takes an average of 5-7 years.