Chiropractic is one of the most widely used health services today. It has gained increasing acceptance as a treatment for back and neck pain, and it is covered by many health insurance plans. Millions of people would report that chiropractic spinal manipulation has brought them relief. Nonetheless, at present the research record for its effectiveness is inconclusive at best.

Daniel David Palmer founded chiropractic in 1895, after an experience in which he apparently believed he cured a man’s deafness by manipulating his back. He opened the Palmer School of Chiropractic and began teaching spinal manipulation. This college still exists today, with a fully accredited program.

One of Palmer’s first students was his son, Bartlett Joshua (B.J.) Palmer. It was B.J. Palmer who truly popularized the technique. Later, Willard Carver, an Oklahoma City lawyer, opened a competing school. He believed that chiropractic physicians needed to offer other methods of treatment in addition to spinal manipulation. This opened a schism in the chiropractic world that still exists today. Followers of Palmer and his methods focus only on spinal adjustments, an approach called "straight" chiropractic. Those who, like Carver, use various approaches to healing are called "mixers." Mixers may use vitamins, herbs, and any other treatment methods they find useful (and are allowed to practice by law).

Medical treatments in the 19th and early 20th centuries were not based on scientific evidence of effectiveness, and chiropractic treatment was no exception. It became a widespread technique long before there was any real evidence that it worked. Chiropractic schools utilized all of their profits and resources to further develop programs for training people in chiropractic techniques—not for verifying the theory and practice of chiropractic. However, in the 1970s, proper scientific research into chiropractic began to draw interest. In 1977, the Foundation for Chiropractic Education and Research (FCER) established a program to train chiropractic researchers. Since then, efforts have been made to fund scientific trials testing the effectiveness of chiropractic techniques and to establish a scientific foundation for the practice.