HISTORY
Kinesiology, pronounced "kin-easy-ology," from the Greek kinesis (motion), was developed by Dr. George Goodheart. In 1964, Dr. Goodheart was treating a young man whose shoulder blade had become dislocated because of a weak muscle. When he pressed those points where this muscle was attached to the rib cage, he found that it was strengthened. Later he discovered that muscles could be strengthened b massaging seemingly unrelated areas of the body.

He devised a theory of "energy circuits" in the body similar to Chinese meridians, and over the years further developed techniques that incorporated cranial and joint manipulation, nutritional advice, and stimulation of acupoints.

Founded in 1974, the International College of Applied Kinesiology (ICAK) has centers throughout the world, including the US, Canada, and Australia. Since the 1970s, kinesiology has attracted interest from osteopaths, chiropractors, nutritionists, dentists, and some doctors. It is now practiced mainly by these and other health professionals.

KEY PRINCIPLES
According to practitioners of kinesiology, the body is an integral, interacting whole. Muscles, organs, and glands are said to be connected via a complex network of energy circuits or pathways, including the nervous, lymphatic, and circulatory systems, and the meridians of Traditional Chinese Medicine. The strength or weakness of certain muscles is said to relate to corresponding body systems, and to indicate the patient's "structural" (physical), "(bio)chemical," and mental health, known collectively as the Triad or Triangle of Health. According to kinesiologists, the muscle's energy circuit "turns off" when an imbalance such as illness, injury, or a "toxic overload" disrupts a particular pathway. Muscles are in a constant state of contraction and relaxation, but if one muscle is weak, its opposing muscle (the one that contracts as it relaxes and vice versa) tries to compensate and may become tense or restrained from overwork.

Practitioners test muscle strength to diagnose imbalances in body system. Physical, chemical, or mental "challenges" are carried out on the body, during which the patient is asked to resist pressure exerted against a limb. Food intolerances and toxicity, in particular, are said to be detected through changes in muscle strength. Nutrients and chemical substances placed directly on the patient's tongue or skin, or homeopathically diluted and contained in a phial placed on the patient's body, are said to stimulate nerve endings and affect energy pathways, triggering muscles to turn "on" or "off."

EVIDENCE AND RESEARCH
Kinesiology is often credited by its supporters with identifying difficult and long-standing health problems undiagnosed by other methods. Some of its basic claims, for example that changes in the nervous system can be linked to "weak" muscles, are supported by research, but many others remain unproved. Efforts to replicate muscle testing in the laboratory have so far proved ineffective.

The practitioner takes a medical history and asks about your diet and lifestyle. Your posture, gait, and any obvious structural imbalance, such as a raised hip, are noted. The practitioner may prefer to test bare limbs to be prepared to remove outerwear.

To test muscle strength, the practitioner uses a relatively large muscle, such as the thigh or bicep, as the "indicator muscle." He asks you to hold your arm or leg in a certain position while he presses against it. If your limb sags or feels "spongy" (weak), further tests are performed to find out why.

• Physical challenge: Pressure is applied to bones and muscles throughout your body if a structural problem is suspected
• Chemical challenge: Foods or homeopathic dilutions of chemicals, viruses, bacteria, or parasites, contained in glass phials, are used to test for toxicity and allergies
• Mental challenge: While you focus on certain thoughts or feelings, the practitioner tests a major muscle.

The length of treatment and number of sessions depends entirely on your condition. It may involve joint manipulation, acupuncture, homeopathic remedies, or nutritional advice, after which your muscles will be tested again for important.

For the muscle test, the practitioner pushes against the "indicator muscle" to test the patient's muscle strength. He may follow this with specific tests on muscles in the body area believed to be the cause of the problem.

In a chemical challenge, a phial of the suspect substance is put on the patient's abdomen and a major arm muscle is tested. For a more specific test, the substance, or a variation of it, is placed under the tongue and the muscle tested again. The practitioner taps the temples to "clear" the body of the effects of one substance before testing another.