Chiropractic doctors are primarily independent practitioners that diagnose and treat patients based on the concept that the nervous system coordinates all of the body's functions. Chiropractors manipulate the spine with their hands to realign the vertebrae and relieve pressure on the nerves. As people age, they are more likely to develop physical conditions that chiropractors can treat, which will become increasingly significant as baby boomers, a large portion of the population, enter their later years.