Applied kinesiology

Applied kinesiology (not to be confused with the scientific study of human movement) is a major chiropractic-based woo that is based on the idea that the way your muscles respond to being pushed against can tell the "doctor" what you're suffering from, including food sensitivity (as distinct from actual immune response), toxins, and electromagnetic hypersensitivity. It has even been claimed that applied kinesiology can detect parasites from "parasite energy signatures". Apparently the practice can also be used to turn your body into a human lie detector. The things these people believe…

(In)efficacy
In general, any treatment or diagnosis administered by applied kinesiology tends to be outperformed by standard medical diagnosis and treatment for the particular condition. For many muscles groups, different kinesiologists were unable to make the same diagnosis as one another, suggesting that the techniques lack any functional unifying theory. For diagnosing nutrition-related problems, applied kinesiology is as accurate as random guesses.

Scam
The applied kinesiology scam is a trick used by some chiropractors and purveyors of "power bracelets" to fool someone concerning the efficacy of an object or therapy. It entails placing someone in an unstable position or touching them in a way designed to momentarily distract them, then pushing or pulling on them to make them unbalanced. The procedure is then repeated, but with the aid of the 'magic' item. However, this time, the subject is subconsciously prepared for the action and is able to successfully resist the pushing or pulling.

A Skeptic Zone Podcast shows how it is done: