You may have seen people doing this in the health food store: One person is holding a product such as a bottle of vitamins with one arm stretched out perpendicularly to their body, and another person is trying to push down on their arm.

They are practicing muscle testing, also known as kinesiology. The theory is that our muscles respond to many external as well as internal influences, becoming stronger or weaker.

In muscle testing, the change in muscle strength is assessed before and during contact with a test item.

The simplest form of muscle testing requires a tester as well as the person to be tested.

How to Test

The tested person sits or stand with uncrossed legs, one hand flat over the navel and the other arm held out to the side, elbow level with shoulder and bent at a right angle.

As the tester, press just above the elbow to push it down. Press the arm lightly into the shoulder as well as toward the hip. If the tested person is very strong, the pressure can be straight down, or the arm can be fully extended and the pressure applied at the wrist. Increase the pressure gradually with measured strength; feel and remember exactly the amount of pressure required to force the arm down. If both arms are weak, you can test the legs.

During testing, keep this questioning mind: Is the tested sample good or bad for the patient? Do not expect a certain result. The preferences of the tested person seem to have little influence on the result, but any expectation makes a difference.

Now the tested person takes a sample vitamin or food and holds it with the free hand just above the navel. After about ten seconds, as the tester, press the arm down and carefully note any difference in resistance. If the result is doubtful, repeat the test with and without the tested person holding the sample. Often a difference is easier to detect if the arm is pressed down three times in succession.