Chiropractors are not normally licensed to write medical prescriptions or perform major surgery in the United States, (although New Mexico has become the first US state to allow "advanced practice" trained chiropractors to prescribe certain medications.). In the US, their scope of practice varies by state, based on inconsistent views of chiropractic care: some states, such as Iowa, broadly allow treatment of "human ailments"; some, such as Delaware, use vague concepts such as "transition of nerve energy" to define scope of practice; others, such as New Jersey, specify a severely narrowed scope. US states also differ over whether chiropractors may conduct laboratory tests or diagnostic procedures, dispense dietary supplements, or use other therapies such as homeopathy and acupuncture; in Oregon they can become certified to perform minor surgery and to deliver children via natural childbirth. A 2003 survey of North American chiropractors found that a slight majority favored allowing them to write prescriptions for over-the-counter drugs. A 2010 survey found that 72% of Swiss chiropractors considered their ability to prescribe nonprescription medication as an advantage for chiropractic treatment.
Among people seeking back pain relief alternatives, most choose chiropractic treatment. About 22 million Americans visit chiropractors annually. Of these, 7.7 million, or 35%, are seeking relief from back pain from various causes, including accidents, sports injuries, and muscle strains. Other complaints include pain in the neck, arms, and legs, and headaches.