Applied Kinesiology (AK) is a form of diagnosis using muscle testing as a primary feedback mechanism to examine how a person's body is functioning. When properly applied, the outcome of an AK diagnosis will determine the best form of therapy for the patient. Since AK draws together the core elements of many complementary therapies, it provides an interdisciplinary approach to health care. During a functional neurologic evaluation, muscle tests are also used to monitor the physiologic response to a physical, chemical or mental stimulus.

Applied Kinesiology's tools range from specific muscle treatments designed to normalize muscle activity to treatments designed to aid other damaged tissues like skin, ligaments, tendons and joints.

The term "functional biomechanics" refers to the clinical assessment of posture, organized motion such as in gait, and ranges of motion. Muscle testing readily enters into the assessment of postural distortion, gait impairment and altered range of motion.

When AK is used with chemical stimulus comprehensive study has shown that the validity of muscle testing and homeopathic solutions including food and environmental substances verifies the testing procedure and outcome.