Chiropractors use their version of spinal manipulation (known as chiropractic adjustment) as their primary treatment method, with non-chiropractic use of spinal manipulation gaining more study and attention in mainstream medicine in the 1980s. There is no evidence that chiropractic spinal adjustments are effective for any medical condition, with the possible exception of treatment for lower back pain. The safety of manipulation, particularly on the cervical spine has been debated. Adverse results, including strokes and deaths, are rare. There are about 200 chiropractic techniques, most of which are variations of spinal manipulation, but there is a significant amount of overlap between them, and many techniques involve slight changes of other techniques. According to the American Chiropractic Association the most frequently used techniques by chiropractors are Diversified technique 95.9%, Extremity manipulating/adjusting 95.5%, Activator Methods 62.8%, Gonstead technique 58.5%, Cox Flexion/Distraction 58.0%, Thompson 55.9%, Sacro Occipital Technique [SOT] 41.3%, Applied Kinesiology 43.2%, NIMMO/Receptor Tonus 40.0%, Cranial 37.3%, Manipulative/Adjustive Instruments 34.5%, Palmer upper cervical [HIO] 28.8%, Logan Basic 28.7%, Meric 19.9%, and Pierce-Stillwagon 17.1%. Techniques Manual and manipulative therapy In the late 19th century in North America, therapies including osteopathy and chiropractic became popular. Spinal manipulation gained mainstream recognition during the 1980s. In this system, hands are used to manipulate, massage or otherwise influence the spine and related tissues. It is the most common and primary intervention used in chiropractic care. Diversified technique Diversified technique is a non-proprietary and eclectic approach to spinal manipulation that is commonly used by chiropractors. The technique, as it is applied today, is largely attributed to the work of Joe Janse Diversified is the most common spine manipulation technique used by chiropractors, with approximately 96% of chiropractors using it for approximately 70% of their patients. Diversified is also the technique most preferred for use during future practice by chiropractic students. Diversified is the only spine manipulation technique taught in Canadian chiropractic programs. Like many chiropractic and osteopathic manipulative techniques, Diversified is characterized by a high-velocity, low-amplitude thrust. It is considered the most generic chiropractic manipulative technique and is differentiated from other techniques in that its objective is to restore proper movement and alignment of spine and joint dysfunction. Atlas orthogonal technique Atlas Orthogonal Technique is an upper cervical chiropractic treatment technique created by Frederick M. Vogel and Roy W. Sweat in 1979. It is a technique which uses a percussion instrument in attempts to adjust what is measured from