How Muscle Testing Works in Applied Kinesiology

The Science Behind Manual Muscle Testing

Muscle testing is one of the most recognisable techniques used in Applied Kinesiology (AK). If you’ve ever visited a chiropractor trained in AK, you may have experienced gentle resistance being applied

to your arm or leg while holding a specific position.

This process is known as manual muscle testing (MMT), a clinical assessment tool used across many healthcare disciplines including chiropractic, physiotherapy, neurology, and rehabilitation medicine. (PubMed)

In this article we’ll explain:

• how muscle testing works

• the neurophysiology behind it

• what scientific research says

• how chiropractors use it during assessment

What Is Manual Muscle Testing?

Manual muscle testing is a clinical method used to evaluate muscle strength and neuromuscular function.

During the test:

1. The patient holds a specific position.

2. The practitioner applies gentle resistance to the muscle.

3. The response of the muscle is observed.

The goal is not simply to measure strength, but to evaluate how well the nervous system activates and coordinates the muscle.

Manual muscle testing has been used in clinical practice for over a century and appears in research literature as early as 1915, with extensive studies examining its reliability and application in musculoskeletal assessment. (PubMed)

Today it remains a common tool in:

• physiotherapy

• sports medicine

• chiropractic care

• neurological rehabilitation

The Neurological Basis of Muscle Testing

Muscles do not work independently. Every movement in the body is controlled by the nervous system, which sends signals from the brain and spinal cord to activate muscle fibres.

When a muscle contracts, several neurological processes occur simultaneously:

• motor neurons activate muscle fibres

• sensory receptors monitor joint position

• reflex pathways coordinate stability

These processes are known collectively as neuromuscular control.

Because of this relationship, muscle strength and coordination can change when there is:

• joint dysfunction

• nerve irritation

• muscle inhibition

• altered movement patterns

Manual muscle testing allows practitioners to observe these neuromuscular responses in real time.

Research has shown that muscle testing can provide insight into the interaction between the muscular and nervous systems, supporting its role as a functional examination tool in musculoskeletal assessment. (SpringerLink)

Muscle Testing in Applied Kinesiology

Applied Kinesiology was developed in the 1960s by chiropractor Dr George Goodheart.

Goodheart observed that certain muscle weaknesses could sometimes be associated with joint dysfunction or other functional imbalances in the body. Over time he developed a system using muscle testing to help guide clinical assessment and treatment decisions.

Within AK, muscle testing is used to identify possible:

• muscle inhibition

• joint dysfunction

• movement imbalance

• neuromuscular coordination issues

Importantly, muscle testing is not used in isolation. Chiropractors trained in AK interpret the findings alongside:

• orthopaedic examination

• neurological testing

• posture analysis

• patient history

This comprehensive approach helps clinicians better understand the functional relationships between muscles, joints and the nervous system.

What Does Research Say About Muscle Testing?

Scientific research into manual muscle testing has examined two key questions:

1. Is the test reliable?

2. Does it provide clinically useful information?

Reliability Studies

Several studies have investigated whether different clinicians obtain similar results when performing muscle testing.

A systematic review of Applied Kinesiology manual muscle testing found reliability ranging from moderate to very strong depending on the muscle tested and testing conditions. (PubMed)

For example, muscles such as the deltoid, gluteus maximus, piriformis and iliopsoas demonstrated particularly strong reliability in testing procedures. (PubMed)

Earlier research has also reported good reliability for manual muscle testing when used in neuromusculoskeletal evaluation. (go.gale.com)

Another study examining the clinimetric properties of AK muscle testing concluded that the technique could reliably identify neuromuscular inhibition patterns, supporting its potential clinical usefulness in musculoskeletal evaluation. (PMC)

Limitations of Research

Like many clinical examination methods, manual muscle testing also has limitations.

Some studies highlight that results can be influenced by factors such as:

• practitioner experience

• test standardisation

• patient effort

Researchers have therefore emphasised the importance of consistent testing procedures and appropriate clinical interpretation. (PMC)

Additionally, while manual muscle testing is widely used for musculoskeletal assessment, the use of Applied Kinesiology as a diagnostic method for non-musculoskeletal conditions remains controversial and requires further research. (PMC)

For this reason, most chiropractors use AK as an additional assessment tool rather than a standalone diagnostic method.

Why Chiropractors Use Muscle Testing

Muscle testing can provide practical information about how the body is functioning during movement.

In chiropractic care it may help identify:

• muscles that are not activating properly

• joints that may be restricted

• areas of compensatory movement

• patterns contributing to pain or injury

This can help guide treatment strategies such as:

• spinal adjustments

• joint mobilisation

• soft tissue therapy

• rehabilitation exercises

The aim is always to improve movement quality, muscle coordination and joint function.

What Happens During a Muscle Testing Assessment?

During a consultation that includes Applied Kinesiology, you may experience several simple tests.

A typical assessment may include:

1. Posture evaluation – assessing spinal alignment and balance

2. Movement testing – evaluating joint motion and mobility

3. Orthopaedic tests – identifying potential injury patterns

4. Manual muscle testing – assessing muscle activation and coordination

Each test contributes information that helps build a complete picture of your musculoskeletal health.

Is Muscle Testing Safe?

Yes. Manual muscle testing is non-invasive and generally very gentle.

The practitioner simply applies light resistance to a muscle for a few seconds while you hold a position.

It does not involve needles, injections, or medication.

When Might Muscle Testing Be Helpful?

Applied Kinesiology may be used during assessment of people experiencing:

• back pain

• neck pain

• shoulder injuries

• sports injuries

• muscle imbalance

• joint stiffness

• postural strain

Treatment recommendations are always based on the full clinical assessment and patient history, not muscle testing alone.

When to See a Chiropractor

If you are experiencing ongoing pain, stiffness, or reduced mobility, a thorough musculoskeletal assessment can help identify possible contributing factors.

Chiropractors trained in Applied Kinesiology may incorporate muscle testing alongside standard orthopaedic and neurological examination techniques.

This approach can help guide a personalised treatment plan focused on improving:

• movement

• comfort

• physical function

Book a Consultation

If you’re interested in learning how chiropractic care and Applied Kinesiology assessment may help you, we would be happy to help.

At New Body Clinic, we provide comprehensive musculoskeletal assessments designed to understand how your spine, muscles and nervous system work together.

📅 Book your consultation today to receive a personalised assessment and treatment plan.

References (PubMed)

1. Cuthbert SC, Goodheart GJ. On the reliability and validity of manual muscle testing: a literature review. Chiropr Osteopat. (PubMed)

2. Conable KM, Rosner AL. A narrative review of manual muscle testing and implications for muscle testing research. J Chiropr Med. (PubMed)

3. Soares JR et al. Reliability of Manual Muscle Testing in Applied Kinesiology. (PubMed)

4. Oliveira DG et al. Clinimetric properties of the applied kinesiology manual muscle test. (PMC)

5. Bittmann FN. Manual muscle test—force profiles and reproducibility. (PMC)