Muscle testing is also known as applied kinesiology (AK) or manual muscle testing (MMT). It is an alternative medicine practice that claims to effectively diagnose structural, muscular, chemical, and mental ailments.

Applied kinesiology (AK) is not a part of the science of kinesiology, which is the study of human body movement.

The basic idea behind AK is similar to one of Sir Isaac Newton’s Laws of Motion, which states, “for every action in nature, there is an equal and opposite reaction.”

AK applies this concept to the human body. This means that any internal issues you may be experiencing would be accompanied by related muscle weakness.

Following this thought process, you should be able to perform a muscle test to diagnose any underlying medical condition. Muscle testing conducted in AK differs from standard orthopedic muscle testing.

Here’s an example: You have a muscle test performed, and your bicep is deemed “weak.”

A person performing the muscle test following conventional medicine might suggest working out your biceps more at the gym. A person following AK principles may suggest that you have this weakness because of an underlying problem with your spleen.

Terms explained

A manual muscle test is a standard clinical exam maneuver used by healthcare professionals to grade muscle strength on a 0-5 scale. It is mainly used to check nerves and muscles after injury or disease.

Muscle testing is a legitimate practice used to check muscular strength. It is, however, not an accepted diagnostic tool or method.

According to several studies, including an older 2001 study on the kinesiology muscle test, some standard orthopedic or chiropractic muscle tests may be helpful in identifying specific muscle-related weaknesses. However, research shows that muscle tests are not helpful for diagnosing medical conditions (such as organic disease or mental illness).

Some exceptions may exist. A 2023 study found that the applied kinesiology muscle test provided accurate results when used to measure sacroiliac dysfunction. The accuracy compared to other types of tests was found to be comparable, but further studies are still recommended to confirm these findings.

How is a manual muscle test usually performed?

Applied kinesiology practitioners may follow the following steps when attempting to diagnose body imbalances by testing muscle strength:

  • The practitioner asks you to hold an arm up and steady while they apply gentle downward pressure, asking you to resist as they do this.
  • You are then instructed to relax.
  • The tester introduces a challenge. For example, they may ask you to think of or touch a body part with the other arm, look at an image, or hold a food or supplement.
  • The practitioner repeats the pressure again, asking you to hold steady and resist.
  • If the muscle momentarily weakens or the resistance feels weaker than initially, they interpret that as a sign of stress, allergy, or organ dysfunction.

The process is quick, subjective, and not supported by scientific evidence for diagnosing medical conditions.

AK began with George Goodheart, Jr. in 1964 as a system of muscle testing and therapy.

Several years later, in a study conducted by Ray Hyman, a group of chiropractors sought to demonstrate that they could distinguish between subjects given good sugar (fructose) and bad sugar (glucose).

A drop of sugar water was placed on a test subject’s tongue. They then measured the strength of each test subject’s arms. The chiropractors anticipated being able to identify which subject had been given the bad sugar based on a muscle test that would show weaker muscles. After multiple failed attempts, they ended the test.

More recently, muscle testing as a diagnostic technique has been debunked again and described as “not conforming to scientific fact” regarding medical conditions, their causes, and treatments.

Who practices applied kinesiology?

In a survey conducted by the National Board of Chiropractic Examiners (NBCE) in 1998, 43% of chiropractic offices in the United States used AK.

Although the majority of practitioners in the survey were chiropractors, occupations also included nutritionists, naturopathic doctors, and massage and physical therapists.

Currently, the Nambudripad Allergy Elimination Technique (NAET) advocates for the use of AK in allergies and other sensitivities.

However, the results of a 2001 study using muscle tests as an allergy test for wasp venom state that it is no more helpful in diagnosing allergies than random guessing.

The medical and research community has not backed the idea of AK as a diagnostic tool for mental or physical conditions.

Until new research yields different results, it is not advisable to place trust in this technique when making important healthcare decisions.