not a raw test of strength, but rather a subjective evaluation of tension in the muscle and smoothness of response, taken to be indicative of a difference in spindle cell response during contraction. These differences in muscle response are claimed to be indicative of various stresses and imbalances in the body. A weak muscle test is equated to dysfunction and chemical or structural imbalance or mental stress, indicative of suboptimal functioning. It may be suboptimal functioning of the tested target muscle, or a normally optimally functioning muscle can be used as an indicator muscle for other physiological testing. A commonly known and very basic test is the arm-pull-down test, or "Delta test," where the patient resists as the practitioner exerts a downward force on an extended arm. Proper positioning is paramount to ensure that the muscle in question is isolated or positioned as the prime mover, minimizing interference from adjacent muscle groups. Nutrient testing Nutrient testing is used to examine the response of various patient's muscles to assorted chemicals. Gustatory and olfactory stimulation are said to alter the outcome of a manual muscle test, with previously weak muscles being strengthened by application of the correct nutritional supplement, and previously strong muscles being weakened by exposure to harmful or imbalancing substances or allergens. Though its use is deprecated by the ICAK, stimulation to test muscle response to a certain chemical is also done by contact or proximity (for instance, testing while the patient holds a bottle of pills). Therapy localization Therapy localization is another diagnostic technique using manual muscle testing which is unique to applied kinesiology. The patient places a hand which is not being tested on the skin over an area suspected to be in need of therapeutic attention. This fingertip contact may lead to a change in muscle response from strong to weak or vice versa when therapeutic intervention is indicated. If the area touched is not associated with a need for such intervention, the muscle response is unaffected. Scientific research In 2015 the Australian Government's Department of Health published the results of a review of alternative therapies that sought to determine if any were suitable for being covered by health insurance; applied kinesiology was one of 17 therapies evaluated for which no clear evidence of effectiveness was found. According to the American Cancer Society, "available scientific evidence does not support the claim that applied kinesiology can diagnose or