Spinal manipulation is a therapeutic intervention performed on synovial joints in the spinal column. The most commonly cited of these are the zygapophysial joints. However, the occipitoatlantal, atlantoaxial, lumbosacral, sacroiliac, costotransverse and costovertebral joints are also synovial joints of the spine that may be manipulated. Spinal manipulation is a therapeutic intervention that has roots in traditional medicine and has been used by various cultures, apparently for thousands of years. Hippocrates, the "father of medicine" used manipulative techniques, as did the ancient Egyptians and many other cultures. A modern re-emphasis on manipulative therapy occurred in the late 19th century in North America with the emergence of osteopathic medicine and chiropractic.