On their first visit, many people are a little surprised when the doctor asks them to stretch out an arm, hold it still, and then pushes gently on the wrist for a few seconds. The question that usually follows right away is: “Is this safe, doctor?” It is a fair question, because the internet is full of “muscle testing” videos, each one doing it a different way.
Physically, muscle testing is gentle and non-invasive. The test itself uses no needles and no injections, so it causes almost no harm. For a muscle testing session to be truly safe, the person doing the testing must be properly trained, and Applied Kinesiology (AK) must sit within a full examination that includes taking your history, a clinical examination, the four examinations of traditional medicine and reading your lab results. Used that way, AK helps the doctor see things that a lab report alone does not show.
What muscle testing is, and what it feels like
AK uses manual muscle testing to assess function. The doctor places your arm or leg in a particular position, you hold still, and the doctor applies moderate pressure in the opposite direction for a few seconds. The doctor watches whether the muscle holds the position steadily or gives way. You don’t need to tense with all your strength. And nobody wins or loses.
It feels like a light exercise in holding a position. If you have acute pain or a recent injury somewhere, the doctor will choose a different muscle, or put off muscle testing until you feel better. If a position is uncomfortable, just say so and the doctor will change it.
The way a muscle responds helps the doctor identify structural, chemical and mental factors, the three sides of the health triangle the clinic uses to trace the chain of causes behind an illness. According to Rosner and Cuthbert (2012), AK uses muscle testing to assess these three aspects, together with standard diagnostic methods.
What AK helps the doctor see
When your lab results are normal but your body still isn’t right
Many people come to the clinic with a stack of lab results that are all within the normal range, and yet they are still tired, still sleep poorly, and their body still isn’t running smoothly. A normal number on paper is not always enough for that particular person’s body to work well, and some tests do not accurately reflect what is going on inside.
This is where the clinic uses AK to check ions (including minerals and electrolytes) and medicinal substances. Walther describes the method in the chapter “Chemical and Nutrition Testing” of the foundational textbook series on AK. You taste or hold in your mouth a small amount of the substance being checked, sometimes you only need to smell it, and then the doctor retests the chosen muscle to see how its response changes (Walther, 1981, pp. 45–50). From this, the doctor learns more about what your body is lacking and what it needs.
In practice at the clinic, some people have normal lab results, yet when checked with AK, the doctor still finds signs that a medicinal substance is lacking. The doctor reads the two results side by side before deciding what needs to be added.
Checking for stress
Long-term stress usually doesn’t show up on a lab report, even though the person feels it very clearly. The clinic uses AK techniques to check for stress in the frontal lobe, the limbic system and the cingulate gyrus. These brain areas take part in emotions and in how the body responds to pressure. The clinic also recognizes that the body stores memories in many different areas of the body, not only in the brain. The results tell the doctor how far mental factors are contributing to the illness, so that treatment does not miss this side of the health triangle.
Therapy localization and challenge
With therapy localization, you place your own hand on an area suspected of having a problem, such as a joint or a part of the abdomen, while the doctor retests a muscle. If the muscle’s response changes when you touch that spot, the area deserves a closer look. When pain is spread out and hard to pinpoint, this helps the doctor narrow down the area quickly.
A challenge, on the other hand, is done by the doctor. The doctor presses or gently pushes a joint in a particular direction, or introduces a substance as in the check for medicinal substances above, and then retests the muscle to see how the body responds. The way the muscle responds helps the doctor choose how to treat. After each treatment step, the doctor can test again to see whether the body has changed.
What makes a muscle testing session safe and reliable
A properly trained tester
Muscle testing is a hands-on skill that takes a long time to master. In trained hands, muscle testing results can be relied on. Cuthbert and Goodheart (2007) reviewed more than 100 studies on muscle testing and AK, and reported evidence of reliability and good validity when muscle testing is used for people with neuromusculoskeletal disorders. A recent systematic review also found that testing certain muscles, such as the deltoid, gluteus maximus, piriformis and iliopsoas, reached reliability ranging from moderate to very strong (Soares et al., 2025).
Rosner and Cuthbert (2012) warned about versions of “AK” spreading outside the field that lack the core elements of the method. Today there are many online videos teaching people to test their own muscles at home. The wrong position, the wrong direction of force or the wrong order easily leads to the wrong conclusion, and then to cutting out foods or taking things you don’t need. If you want to be checked with AK, look for a place with a doctor trained in AK.
AK within a full examination
At Tam Duc, muscle testing never stands alone. It always comes after taking your history, the examination, and reading the lab results and imaging you bring; each step is described in our article What to bring and how to prepare for an Applied Kinesiology visit. Writing about the neurological basis of AK, Schmitt and Yanuck (1999) regard muscle testing as an extension that adds to the neurological examination and standard diagnostic methods.
There are things the clinic does not use muscle testing to replace:
- Diagnosing an organic disease (one with a physical cause that tests can show);
- Lab tests and imaging, when the doctor sees a need for them.
Here, AK adds to lab tests, imaging and medical diagnosis. We do not treat AK as a mysterious energy therapy on its own, we do not promise that AK cures every illness, and we do not advise anyone to diagnose themselves at home. How the clinic combines its methods is explained on our Our Approach page.
When to seek care right away instead of waiting for your appointment
Some signs need to be handled at the nearest emergency department or hospital, before you think about any muscle testing session:
- Chest pain, chest tightness, shortness of breath;
- Sudden weakness or numbness on one side of the body, a drooping mouth, or difficulty speaking;
- A high fever that lasts and won’t come down;
- Severe pain after a fall or injury, especially if you cannot move.
This list does not cover every situation. If something feels wrong with your body and it is getting worse quickly, go and get checked right away; we can talk about long-term treatment later.
Frequently asked questions
Does muscle testing hurt?
You won’t feel pain, because the pressure is only moderate and lasts a few seconds. If a position hurts because of a condition you already have, the doctor will change the position or choose a different muscle.
Can children, older adults and pregnant women have muscle testing?
Yes. The doctor adjusts the pressure and chooses muscles to test that suit each person, and never pushes on if you feel uncomfortable. For someone who is pregnant, the doctor chooses which areas to check depending on how far along the pregnancy is. Later in pregnancy, the doctor does not test the muscles of the pelvic area.
Can I test my own muscles at home?
We don’t recommend it. Muscle testing takes skill, and the results need to be read together with your medical history, the clinical examination and your lab results. Testing yourself by following videos can very easily lead to the wrong conclusion.
Can muscle testing replace lab tests?
No. Lab tests and imaging show things that muscle testing cannot measure, while muscle testing helps the doctor look at how your body is functioning. That is why the doctor always wants to see the lab results you already have.
Dr. Dinh Ngoc Duc (MD, MSc in Traditional Medicine) is responsible for the medical content of this article. He uses AK in his examinations and has attended ICAK (International College of Applied Kinesiology) conferences.
References
- Walther DS. Applied Kinesiology, Volume I: Basic Procedures and Muscle Testing. Pueblo: Systems DC; 1981. Chương “Chemical and Nutrition Testing”, tr. 45–50.
- Rosner AL, Cuthbert SC. Applied kinesiology: distinctions in its definition and interpretation. J Bodyw Mov Ther. 2012;16(4):464-487. https://doi.org/10.1016/j.jbmt.2012.04.008
- Cuthbert SC, Goodheart GJ. On the reliability and validity of manual muscle testing: a literature review. Chiropr Osteopat. 2007;15:4. https://doi.org/10.1186/1746-1340-15-4
- Soares JR, Stieven FF, Rocha CSDS, Miranda IF. Reliability of Manual Muscle Testing in Applied Kinesiology: A Systematic Review. J Manipulative Physiol Ther. 2025;48(6-9):862-870. https://doi.org/10.1016/j.jmpt.2025.10.007
- Schmitt WH, Yanuck SF. Expanding the neurological examination using functional neurologic assessment: part II neurologic basis of applied kinesiology. Int J Neurosci. 1999;97(1-2):77-108. https://doi.org/10.3109/00207459908994304
