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The Science Behind Muscle Activation Techniques

Muscle Activation Techniques (MAT) is a system designed to evaluate and treat muscular imbalances.

MAT has taken basic components of physiology and biomechanics and transferred them into a systematic approach for evaluating and treating the biomechanical relationships relating to chronic pain or injury.

The evaluation and treatment procedures developed by MAT is substantiated and validated by many components relating to muscle physiology. The program is based upon the monitoring and restoring the capability of muscles to contract.

When a muscle is placed on a stretch

When looking at the physiology of a muscle contraction, as the muscle (extrafusal fibers) is placed under a stretch, the muscle spindle (intrafusal fibers) sense tension as they are also placed under a stretch. The sensory receptors that encompass the intrafusal fibers send information back to the CNS, stimulating the alpha motor neuron, which in turn, sends feedback back to the muscle telling it to contract in order to resist the tension. This is a normal response to a muscle when placed on a stretch.

When a muscle is contracting

In comparison, if the extrafusal fibers of a muscle shorten due to contraction, the muscle spindle or intrafusal fiber would also shorten and be placed on a slack. This in turn would make the muscle incapable of regulating the load being placed on the muscle. An adaptation by the CNS, allows for increased gamma motor neuron stimulation resulting in increased feedback to the intrafusal fibers. The intrafusal fibers resist the shortening, increasing the stimulation of the alpha motor neurons, again creating the feedback loop which allows the muscle to accommodate the load. This is the normal spindle response when a muscle is contracting.

The foundation to MAT’s evaluation and treatment process

If a muscle has been traumatized, due to factors such as trauma or overuse, the sensitivity of the spindle will be lessened and the muscle will become less capable of regulating tension relative to a stretch or a load. The result is a reduction in the gamma motor neuron stimulation allowing the muscle spindle to shorten as the extrafusal fibers contract. The more that the muscle shortens, the greater slack and less responsive is the muscle spindle. This results in decreased proprioceptive input into the muscle as it moves into this position.

The actin and myosin crossbridging excessively overlap, creating inefficiency in the muscles’ capability to contract as it moves into the shortened range. Also, relative to biomechanics, the muscle has its greatest mechanical advantage when a 90 degree force angle is created. This results in a decreased force output from the muscle as the force angle moves away from 90 degrees. Therefore, both neurologically and biomechanically, when a muscle has been traumatized, and has altered feedback from the nervous system, there is a reduced capability for the muscle to contract as it moves into the shortened position.

The goal during the evaluation process is to determine whether or not specific muscles that support a joint have proper neurological input necessary to perform its function.

Whether acting as a prime mover, synergist or stabilizer, each muscle must be capable of performing its function as forces are being placed upon a joint. If a muscle does not have proper neurological input, then it will not be able to perform its function efficiently and this leads to positions of vulnerability. The goal of the MAT evaluation process is to find out where the body displays these positions of vulnerability or weakness.  

MAT range of motion (ROM) exam

MAT evaluates weakness by conducting a joint range of motion (ROM) exam. This evaluation of ROM is designed to identify for limitations in motion along with the identification of asymmetrical motion.

The philosophy behind the MAT ROM exam is that when muscle tightness is noted, it is a representation of muscle weakness as opposed to muscle tightness.

Rather than looking at the cause of ROM limitations being caused by muscle tightness, the limitation in motion is addressed as a weakness in the muscle or group of muscles that move the joint into the position of restriction. This philosophy works off of the concepts related to the Law of Reciprocal Inhibition.

Law of Reciprocal Inhibition

This law states that when a muscle contracts, it sends an inhibition response to the antagonist muscle in order to allow for normal joint motion. This law is true, based upon the assumption that normal neurological input is being sent to the contracting muscles. Therefore, if proper neurological input is not being sent to the contracting muscle or group of muscles, which could be caused by a variety of potential factors, then the impulses that would inhibit contraction of the antagonist muscles will also be affected. This allows for the muscle spindle of the antagonist muscle to become more active, which in turn becomes more tonic. This increase in tonicity of the muscle results in muscle tightness.

The philosophy of MAT is substantiated by the Law of Reciprocal Inhibition

If a contracting muscle does not have proper feedback from the nervous system, then the opposing muscle will become hyperactive and its resting length will be altered. The goal with MAT is to provide proper balance between the agonist and antagonist muscle, in order to not only enable adequate motion, but to also allow for adequate strength and stability throughout that ROM. When a muscle has had altered feedback from the nervous system, its capability to contract efficiently becomes altered, therefore, mobility and stability are both negatively affected.

The thought process behind MAT

To properly understand MAT, you must consider many factors. If the proprioceptive input to a muscle has been altered, then the tension of the opposing muscle has also been altered.

  • If you increase ROM in the tight muscle, through stretching or massage, have you improved the capability of the opposite muscle to contract? Also, how do you know?

MAT is a system of checks and balances.  A systematic approach designed to allow practitioners to check their work. This is why the joint ROM exam is so vital. If you see a limitation in joint motion, then you must consider two factors: What muscle or group of muscles is tight, along with, what muscles are not able to function properly that may have caused the antagonist muscles to tighten up? This goes back to the physiological foundation that states that an inhibited muscle has the least amount of proprioception as it moves into the shortened position. This can make a muscle very inefficient as it moves into the shortened range.


Since the muscle is so inefficient in this position consider the following questions:

  1. Why would the body let the joint move into this unstable position?
  2. Is the tightness a form of protection by the body, not allowing the joint into the position of instability?

That is what the MAT evaluation and treatment is based upon. The joint ROM exam provides information to let the practitioner know what motions the body is protecting itself from.

The goal of MAT is to identify these areas of protection and attempt, not only to improve mobility, but also to improve the stability through the new found motion.

Another consideration

  • If the motion in the tight muscle is increased by any modality, how do we know if we have violated part of the body’s protective mechanism?

Why MAT works as a great adjunct to all forms of therapies

  • It is vital that when ROM is increased through modalities such as stretching or massage, that there is also stability through that increased range!

MAT provides the checks and balances system to make sure that this happens.

After the ROM exam

The ROM exam is designed to evaluate joint motion in all positions of extremes in order to determine where the body cannot achieve its motion. The information from the ROM exam gives the practitioner an idea of what muscle or group of muscles may not be functioning at optimal levels.

Once a limitation of ROM is identified, then the particular muscles that move the joint into that position must be evaluated in order to determine if there is proper neurological input. It involves the evaluation of strength of the muscles in their shortened range.

The tests are performed as isolated muscle strength tests, however, with the MAT approach; the concept behind conventional isolated strength testing has been altered.

MAT is looking to identify positions of instability. Based upon what has been addressed, these positions of instability will display themselves in the shortened position of a particular muscle. Therefore, the isolated strength tests are performed in the shortened position of each muscle. This shortened position is also a “position of extreme”. To my knowledge, evaluations of strength are not typically performed in extremes of ROM.

It is important to note that by moving into the shortened position, there is more of a chance that the shortened muscle is being emphasized. Although there are other muscles that may work synergistically with the identified muscle, a weakness in a particular test demonstrates that the muscle that emphasizes the motion is inhibited.

  • MAT strength tests are not designed to evaluate directly for levels of strength. It is a neuro-proprioceptive response test designed to evaluate whether there is proper neural input to the muscle or group of muscles which provide stability in the extreme of motion.

It is not a true “strength” test, since it is an evaluation of whether or not a muscle can contract when a force is applied, as opposed to an evaluation of how strong the muscle is.

Conventional muscle strength testing is usually based upon the foundation of “break testing”. With break testing, the practitioner typically continues to ramp the load being applied to the muscle until the muscle can no longer withstand the force. Studies have shown that in break testing the force applied can exceed 75 lbs of force. With neuro-proprioceptive response testing, the practitioner is trained in precision so that at no time should the force applied surpass 30 lbs of force.

MAT muscle testing is a form of evaluation designed to see:

  1. Can a muscle contract.
  2. Can that muscle contract now, on demand, rather than determining the strength of the muscle.

Timing plays a key role in neuro-proprioceptive response testing. It provides an indication of whether a muscle has proper neural input to adapt to forces applied in every day function.

Why MAT Works

Adapted from material courtesy of Greg Mack, RTSm, MATm, Physicians Fitness


The human body is made up of numerous muscles and joints that allow it to move.  Each joint has an ability to move through a structure-determined specific range of motion (ROM) when the muscles contract in response to our needs during movement.  Although joint structure/muscle capabilities vary between individuals depending on many factors (i.e, genetics, previous injury, surgery, disease, etc.,) motion capabilities for all humans are dictated by the ability of the muscle system to contract in response to a force imposed demand.

When the body is subjected to trauma, which can come in either chronic or acute form, and can have components of chemical, emotional and mechanical stressors, the nervous system can direct a muscle, or group of muscles to lose their full contractile ability via loss of gamma motoneuron drive.   The gamma motoneuron is part of the fusimotor system, which also contains the muscle spindle. The gama moto neuron creates tension on the intrafusal fibers which in turn tense the muscle spindle.  The function of the muscle spindle is to provide sensory information back to the Central Nervous System (CNS) about a specific muscle’s position and rate of change of movement.  The muscle spindle needs to have tension on it in order to provide sensory input.  When a muscle is functioning optimally, it will create tension on the spindle throughout the ENTIRE contractile range of a muscle.

Due to the structure of the muscle spindle, when a muscle is lengthened, the spindle is also stretched and will relay its position to the CNS.  This is partly what you feel when you stretch a muscle.  However, when a muscle is fully shortened, the spindle can become “unloaded,” or slack, if the gamma moto neuron is not functioning properly and is unable to create tension on the intrafusal fibers. This is called muscle inhibition.  An inhibited muscle can also be thought of as a muscle that is neurologically “weak.”

Gamma moto loss as a direct result from trauma has been well documented by research. (Wheeless, textbook for orthapaedics, sensory role for cruciate ligament)  It is hypothesized by Greg Mack, RTSm, MATm, that gamma moto loss after trauma is due to an energy conservation strategy by the body.* (Greg Mack, Neural Sensitivity Document).  Because gamma moto loss will typically affect only part of a muscle’s available contractile range, the shortened range, and, at any given synovial joint there are multiple muscles that can move a joint through multiple planes to create motion, the body may choose to temporarily lose some fine motor control in order to direct it’s available resources to repairing the part of the body most directly affected by the trauma.

While this may be a perfect short term solution, the inability of a muscle to communicate with the CNS throughout its entire range, (i.e. a weak muscle), will eventually have consequences.   At a given joint, every muscle that crosses that joint needs to be able to contract at some point in a range to provide proper control of the joint.   If one or more muscles are inhibited at that joint, and are not  fully available to do so, the stability of that joint is compromised.  This is called instability.

This instability can cause the CNS to restrict motion around that joint and/or related joints as a form of protection from moving into a position it cannot control.  Uncontrolled motion is the essence of injury.

When the inhibited muscles are not sending a signal to the CNS throughout the shortened parts of their range, the CNS will sense that that joint related to that muscle is unstable.   As a result, the CNS will systematically tighten up surrounding muscles around the joint or related joints, thereby limiting mobility.

When mobility is decreased, the body will still try to perform the tasks we are asking it to do.  To do so, it must begin to compensate either by overusing certain muscles, or moving only through certain planes.  Both of these scenarios will cause further muscle inhibitions and accelerate connective tissue (tendon, ligament) and joint surface wear, which will lead to tendonitis, arthritis and increased levels of inflammation within the body.

The tension that is created by the CNS creates that “tight” feeling in a muscle that causes discomfort for many people.  As opposed to stretching, or other modalities which attempt to  “shut off” the tight muscles, which are only tightening up to help keep the joint stable, the MAT process identifies the muscles that have lost their gamma moto drive and seeks to “jumpstart” these muscles in order to recalibrate their communication ability with the CNS.

When proper neuromuscular communication is reestablished, and the CNS recognizes the joint is now stable, tension on the “tight” muscles is reduced, thereby allowing more joint mobility.

There are many times where the body is able to repair itself, and recalibrate fusimotor function, especially when we are younger.  However, due to the amount of stressors we are subject to on a daily basis, further stressors of any kind, mechanical, chemical, can exceed the bodies threshold, resulting in, among other things, muscle inhibition.

It is at this point where MAT seeks to gently intervene

The Muscle Activation Techniques™ (MAT)* process does this by:
1. Assessing joint range of motion throughout the body
2. Identifying asymmetrical loss of joint ROM when comparing right and left sides
3. Determining the individual muscle weaknesses associated with the limitation in        a joint for a given ROM through muscle testing.
4. Reestablishing the muscle’s ability to contract and cooperate with the other muscles acting upon that joint.

1. The MAT process begins with a systematic joint Range Of Motion exam (ROM) throughout the body.  A range of motion exam may be limited to a certain quadrant of the body (upper, lower, trunk, etc) depending on a client’s presenting issues.

2. Using the range of motion exam it is possible to identify ROM deficits when comparing right and left sides.  There are several issues that can lead to ROM loss.  Calcium deposits, bone spurs, nerve tissue excursion.  However, most often it is the result of increased muscle tightness limiting joint motion

-The foundation of MAT is looking at muscle “tightness” as a compensatory response to a neurological muscle weakness (loss of proper fusimotor function, muscle inhibition). 

3. Upon finding a limited joint ROM, a MAT professional will then begin to test the neurological contractile ability of the muscles associated with creating that specific ROM, in order to expose any muscles that are not contracting properly.   The MAT muscle tests are designed to emphasize a specific muscle, typically in its shortened range.  Muscle tests are performed manually to test a muscle’s ability to contract on demand, rather than its maximum force output.

4. When a muscle tests weak, the next step is to manually palpate that muscle’s attachment sites.  Palpation on the attachments sites, rather than the muscle belly itself is done for a few reasons.  Namely, palpating directly into a muscle can be enough to cause muscle inhibition, i.e. autogenic inhibition.  Palpating at the tendonus insertions creates less tissue disturbance; it causes only a slight stretch of the muscle spindle which, in turn, directs the muscle to contract.

Specific gentle isometric contractions also have the ability to recalibrate fusimotor function.  The isometric positions have been carefully designed to put the given muscle in its shortened position.  When the muscle is asked to contract in that position, the only tissue that still has length left to contract further are the intrafusal fibers. When a muscle tests weak, it appears to be due the gamma moto neurons inability to keep tension on the muscle spindle in this shortened position.   Using sustained, repetitive, client initiated, low level force, in these specific positions, provides enough stimulation to the specific low level capacitance of the gamma moto neurons to fire properly again, and to increase their tension on the intrafusal fibers.

After the palpations or isometrics have been performed, that same muscle test is performed to ensure that that proper function has been restored to that specific tissue, and the muscle testing position is now stable.

When proper neuromuscular communication is reestablished, and the CNS recognizes the joint is now stable, tension on the “tight” muscles is reduced, thereby allowing more joint mobility, while maintaining joint stability.

A muscle system that is performing optimally will help reduce systemic inflammation in the body.

The ultimate goal of MAT is to ensure that the muscles and joints on both left and right sides of the body enjoy mobile and stable motion thus leading to optimal, pain free human movement.

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