Joints are balanced by two opposing sets of muscles called antagonists. Muscle inhibition occurs naturally within the nervous system to allow movement to occur. For example, in order for the biceps to flex, the triceps muscle must turn off so that the elbow can bend. This reciprocal muscle inhibition occurs every time you move. When this neuromuscular reflex is dysfunctional, chronic pain and muscle strain patterns are more likely to occur.
Reciprocal inhibition and Reciprocal innervation
Reciprocal inhibition and reciprocal innervation are early scientific terms used to describe the nervous system’s coordination of muscle function that makes movement possible. The first term; reciprocal inhibition occurs when an opposing muscle group is actively inhibited to prevent it from working against the intended muscle’s function. These terms describe the neuromuscular activity that occurs when muscles on one side of a joint relax as muscles to contract on the other side of that joint. For example, when you flex your bicep, your tricep must be inhibited for the elbow to bend. This inhibition is accomplished between receptors and an inhibitory interneuron in the spinal cord. This means the stretch info doesn’t go up to the brain. Instead, an immediate reflexive response to the stretch challenge is possible.
Functional muscle inhibition
Muscle inhibition is important for movement. If opposing muscles contract at the same time, there is no directional movement. Instead, force is directed into the joint, compressing it. Under these circumstances, joint damage occurs faster and muscles can tear easier. During physical activities, antagonists are engaged and disengaged rapidly under load. Reciprocal inhibition facilitates movement and protects against injury. The muscle spindle and the golgi tendon organ receptors protect the muscles, joints and ligaments by creating reflexive contraction or inhibition in muscles. Both the muscle spindle and the GTO elicit reflexive responses that are necessary in coordinating controlled musculoskeletal movement. When stimulated, the muscle spindle elicits the stretch reflex and the GTO elicits an autogenic inhibition reflex.
The Stretch reflex and Autogenic inhibition
The muscle spindle and the GTO’s reflexes oppose each other and are therefore functionally antagonistic. Both receptors protect the myofascial unit which includes the muscle, tendon, fascia and investing joint capsules, ligaments and periosteum. The muscle spindle protects muscles and joints from too much stretching so that muscles don’t tear. The GTO protects tendons from too much contraction so they don’t tear. These intertwined functions are coordinated by the nervous system. Arthrogenic muscle inhibition (AMI). It is a protective mechanism that helps the body to avoid use of the injured joint.. Damage to ligamentous, boney, and mensical structures combine with swelling and pain to disrupt sensory input. The motor side of the system is shut off to protect the joint. Patients are unable to fully contract (e.g., neurologically engage) their muscle during exercise due to inhibitory signals flooding the spinal cord.
Unfortunately, this inability to fully contract the muscle limits our progress in rehabilitation. Further, our ineffective muscle-centric approaches (e.g., quadriceps strengthening programming) treat the symptom of muscle weakness, and not the neural source of the impairment.
The Muscle spindle and The GTO
Muscle spindles detect changes in muscle belly length. They convey these changes to the Central Nervous System which responds by activating motor neurons in the antagonist muscle, making it contract to resist over stretching. The Golgi tendon organ (GTO) is a receptor that senses changes in tension at the tendon. The spindle is located in tendons at the origins and insertions of skeletal muscles. GTO inhibition is experienced as a sudden relaxation of muscles under high tension and stress. It is an autonomic inhibitory lengthening response that protects the tendon from tearing. The stretch reflex is a neurological feedback mechanism that decelerates muscle stretch by causing an antagonistic muscle contraction. In contrast, the GTO reflex is a feedback mechanism controlling muscle contraction. It causes muscle relaxation before tendons can rupture. Although the GTO reflex is less sensitive than the stretch reflex, it can override the stretch reflex when tension is great, for example, causing a person to drop a very heavy weight.
The Muscle Spindle
The spindle’s stretch reflex operates as a feedback mechanism to stop a muscle from over stretching. This muscular response is ubiquitous and applies to quick stretching motions that occur in acute trauma and prolonged over stretching as found in unbalanced posture. If a person sustains a whiplash injury from rear impact, the neck flexors that can’t decelerate the the force of extension via eccentric contraction will tear. Likewise, If a person constantly leans to any one side, the postural muscles connected to the vertebral column on the opposite side will stretch. The muscle spindles in those muscles will detect this stretching, and the stretched muscles will contract to support the head.
The Golgi Tendon Organ
In a GTO reflex, too much contraction force causes the muscle to simultaneously lengthen and relax (inhibit). The GTO reflex is also called the the Autogenic inhibition reflex or the inverse myotatic reflex. Autogenic inhibition created by the GTO reflex is experienced as a sudden relaxation of muscles after the stress of high tension. It is an autonomic inhibitory, lengthening reaction that protects the muscle against tearing. The tendon reflex operates as a feedback mechanism to control muscle tension by causing muscle relaxation before muscle force becomes so great that the tendons might rupture. Just type the words “weightlifting”, “gym” or “workout” followed by the word “fails” into the Youtube search window to see examples of this phenomenon in action.
Why you aren’t getting better
Muscle inhibition creates instability and compensation in the body. It is a problem that plagues physical therapists and bodyworkers. Unbeknownst to many practitioners of physical medicine, the underlying cause is neurological dysfunction between the CNS, the muscle spindle and GTO. This is why stretching inhibited or overstretched muscles and joints can cause the body to respond by making joints and muscles lock down even tighter. Massage and bodywork performed on dysfunctional tissues can be perceived as a threat to the body. Many well intentioned practitioners are manually overriding a compensation program that is neurological in nature. Pain and dysfunction can only resolve after functional communication is restored between the peripheral and central nervous systems. Massage and manual manipulation become less painful and more successful. Attempts to create stability by strengthening neurologically inhibited muscles are in vain and cause faulty compensation patterns to emerge.
How inhibition shows up
Muscle inhibition can occur for a few reasons. The diagnosis of inhibition based on mechanical compression of nerve roots is based on science from the 1940’s. When a nerve is damaged enough, it will cease to transmit signals and muscles control is lost. This belief is unfortunately still prevalent in medicine and often leads to an unnecessary surgery that doesn’t restore strength. This doesn’t change the fact that inhibition without extensive nerve damage is prevalent. True muscle inhibition where there is no volitional control over a muscle or movement. The problem is the diagnosis has been a medical red herring for years. Using the right functional assessment techniques, one can find the source of neurological inhibition and restore lost strength.
Prolonged stretching of muscles causes the nervous system to adapt the muscle’s load. We all know too much sitting is bad. But why? The gluteal muscles settings change as their resting length and contractile potential adapt to the new stretched posture. The less the gluteal muscles are activated, the less space in the brain is allocated to them. Underused movement (motor control) pathways get “forgotten”. Inevitably, the cycle perpetuates itself and synergistic extensors of the pelvis (hamstrings) get recruited to do the job. The lumbo-pelvic hip complex becomes destabilized and then, the low back and hips get involved. Posture adapts to compensate for the imbalances and movement becomes inefficient. Less movement leads to more postural adaptation and so on and so on.
If you pay attention long enough, you may find that there are common and predictable structural and postural reflexes found in bio-mechanical compensation patterns. This phenomenon is termed regional interdependence. This is where an imbalance in one structure will beget a predictable imbalance in a structure elsewhere in the body. There are laws of Spinal motion and reflexive fixation patterns in key bones (or keystones) in the body. Restoring alignment to these bones creates a systemic trickle down and release many locked structures all over the body. There are forms of Chiropractic and bodywork that focus on mobilizing only one or two bones as a complete treatment.
The most elusive type of muscle inhibition occurs when there is dysfunction in the processing of signals throughout the nervous system. The result is muscle weakness. Trauma can often cause these processing errors. Trauma can come from chemical, emotional or physical sources and can be hard to resolve. The nervous system interpretes trauma as a threat. Its source can be acute or repetitive. The response to the threat eventually becomes hard wired. When a stimulus triggers dysfunctional pathways in the nervous system, muscle weakness occurs. Certain stressors regardless of physical, chemical or emotional origin will trigger a relational inhibition response within certain muscles in the body. Underlying dysfunctions must be taken into account prior to manual tissue manipulation in order to resolve chronic issues.. Sometimes even after in order to provide complete resolution of neuromuscular and musculoskeletal dysfunction.
Arthrogenic muscle inhibition
AMI is an ongoing reflex reaction of the muscles around a joint after injury to the structures of that joint. AMI is an often-unrecognized consequence and limiting factor in the rehabilitation of joint injury. It results in atrophy and deficiencies in strength and increases the susceptibility to further injury.AMI is one of the classic complications occurring in the aftermath of knee trauma. It is experienced as a lack of knee extension due to quadriceps inhibition and hamstring contracture, with knee extensor peak torque decreasing by 80 to 90% one to three days after knee joint surgery. Despite diminishing over time, residual levels of AMI may persist as long as 4 years after initial joint trauma.Its origins remains unknown to most doctors with a strong suspicion for a central brain origin. A therapeutic intervention resulting in decreased inhibition (facilitation) , allowing for active exercise, would lead to faster and more complete recovery. I treat it effectively through the nervous system.
Reverse Muscle Inhibition For Good
20 years of clinical work with people in pain have convinced me that most muscle inhibition, recalcitrant joint fixations and stubborn hypertonic muscles are driven by neurologically created compensation patterns. Muscle inhibition patterns are created within the nervous system and can’t be addressed with manual bodywork.Most therapists attempt to reverse the effects of dysfunction via tissue manipulation and exercise. I go to the source of the dysfunction first. The outcome is always that less painful, deep physical manipulation is necessary and I get greater results faster than with manual massage and bodywork alone.
NYOM Spells Relief
NYOM’s cutting edge integration of neuromuscular and manual tissue manipulation addresses the issues that linger after “expert” rehab or treatments. I look for and find things that others don’t that are preventing the body from a full recovery. The therapeutic limits of massage and manual therapy don’t apply after you address the neuromuscular inhibition patterns that create musculoskeletal dysfunction and pain. Stop chasing symptoms and address the source of the problem with a Neuro-Orthopedic session today!