Science

The Basics of the Neuromuscular System

The nervous systems primary role is communication throughout the entire body. Whether it’s giving or receiving information from digesting food throughout your gastrointestinal system to raising/decreasing your heart rate from running or walking. There are billions of these communications occurring simultaneously every second. For the muscular system alone, there is constant communication being made for lengthening and shortening muscles for the human body to perform even the most simple tasks.

Unfortunately, not everyone has all of these muscles working for them on a given day. When this happens, “compensation” in the muscular system takes place. This is when muscles have to take over the work of other muscles that are meant to do the initial work that was intended. Think of it as having employees doing more work than what they signed up for. Instead of hiring more workers, they just get more work to do. Communication will deteriorate and eventually very little work will get done.

Every now and then, the nervous system loses its ability to communicate with some of the muscles in the body. When this happens, these muscles cannot contract fully on demand. This is commonly known as muscle inhibition. This impaired communication can be caused by many factors; however, the usual suspects are mechanical stress, trauma or overuse.

The reality of today with the amount of stress placed on our bodies due to lack of sleep, nutrition, overtraining, injuries, trauma, our daily activities etc., can cause the nervous system to lose its ability to communicate with certain muscles in the body. Now that these muscles are inhibited to contract fully on demand, it causes other muscles to take over by compensation which creates tightness and instability.

The Science Behind MAT™

Muscle Activation Techniques (MAT™) has taken basic components of physiology and biomechanics while transferring 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 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 to send information back to the CNS, stimulating the alpha motor neurons, 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.

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.

NOT Normal

If a muscle has been traumatized or gone passed its force threshold, 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.

Force Application

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.

This information has become the foundation to both the evaluation and treatment processes related to MAT™. Relative to the evaluation process, the goal is to determine whether or not specific muscles that support a joint have the 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 mechanically 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.