The Role of Proprioceptors In Joints and the Brain
This is the third in an ongoing series on the therapeutic applications of yoga to appear in LA YOGA Ayurveda and Health Magazine.
As Patanjali’s Yoga Sutra 1.2 says, “Yoga is the mastery of the activities of the mind-field;” or “Yoga is about controlling the fluctuations of the mind.” Okay, how do we go about doing this? The physical aspects of yoga practice are vitally important for the health of both body and mind.
At this point in history, through imaging technology, we now have a deeper understanding of the physiology of the body and, through that, insight into what ancient disciplines taught in their sacred texts about improving concentration and decreasing stress. The key to ushering in a new wellness revolution may be found in our spine, our joints and muscles, and the communication of these parts of the body with the brain.
Phenomenal research by Dr. Jeremy Schmahmann PhD shows that movement of the spine stimulates a part of the brain, the cerebellum, which is responsible for coordinating full-body movement, thoughts, feelings, emotions and the healthy functioning of the organs and the immune system. This reveals how yoga and other healing movement disciplines and modalities such as chiropractic are vital for those striving to achieve total health.
The cerebellum is stimulated through the spinocerebellar tract by specialized mechanoreceptors located in the joints throughout the body. Two main types of mechanoreceptors are proprioceptors and nociceptors.
Proprioceptors are nerve cell receptors found in muscles, tendons and joint capsules, which give information concerning movements and the position and alignment of the body. The highest concentration of proprioceptors is in the spine, with the greatest amount being clustered in the upper cervical spine. (200% more are in the upper cervical spine than any other place in the body.)
Knee Joint
When a joint moves, the brain wants to know if the movement was healthy and beneficial or damaging or dangerous. If you move a joint correctly or in a healthy way, the proprioceptors fire a signal to the cerebellum where the magic happens. The magic is the integration of body and mind. With healthy proprioception the nervous system obtains information and physiological functions can be expressed naturally. These include: spinal movement, pleasure and pain, our relationship to gravity, balance, limb position in space, vibration, pressure, fluctuations in blood volume, neuro-chemical releases in the brain, the immune system, GI tract, and autonomic changes in the nervous system and our homeostasis. The result is a higher level of health, healing and connectedness.
This is huge when you realize that healthy movement of the spine, and stimulation of the proprioceptors, is like rocket fuel because it stimulates the part of the brain responsible for coordinating your thoughts, feelings and movements. The part of the brain that processes movement is the same part of the brain that processes learning.
The more the brain is stimulated, the deeper the connections. Deeper grooves are created with the repetition of specific stimulations. This is how the brain becomes hardwired and this is why movement disciplines are so vital. Movement of the spine and subsequent stimulation of the cerebellum can also influence behavioral changes. These behavioral effects include: processes of attention, motivation, language, memory, vision, emotion and learning. All those sun salutations are doing just as much for your mind as they are doing for your body. This is particularly the case when they are done correctly, without jamming the joints and without forcing the bones together or moving the bones against the grain.
With healthy proprioception and spinal movement, information about pleasure and pain, our relationship to gravity, balance, limb position in space, vibration, pressure, fluctuations in blood volume, neurochemical releases in the brain, immune system, GI tract and autonomic changes can be expressed naturally. The result is a higher level of health, healing and connectedness.
When two bones come together they form a joint. Movement is determined by the shape and depth of the joint, as well as the tightness of the capsule, ligaments and muscles associated with the joints. If a yogi moves the bones against the grain, or incongruent with the shape of the joint, then a jamming effect can occur. We commonly know of this as a sprained joint or strain in the muscles or ligaments.
When joints slam or jam into each other, proprioceptors don’t fire. Rather, nociceptors, or noxious stimulation receptors, get activated and the stress response is triggered. Believe it or not, stuck, jammed or misaligned joints create the same physiological response as being put into a fight or flight situation when your life is in danger. Your heart rate quickens, your cardiac output increases, there’s a flood of adrenaline, cortisol, insulin and a laundry list of other negative responses. You see, your body has two main programs it can run – growth and repair or fight or flight. If you are being chased by a saber tooth tiger (fight or flight/stress response) and at the same time healing from a viral infection (growth and repair/immune response), your body will choose to run the program that is more important. It can only be one or the other. Obviously surviving a vicious attack from a saber tooth tiger is more important that fighting off a viral cold. Misaligned bones activate the stress response and turn off your immune response. That’s all from a headstand or upward facing dog gone badly or hours slouched over a computer. Who knew?
Stuck, jammed or misaligned joints create the same physiological response as being put into a fight or flight situation when your life is in danger.
Jamming joints can happen in more than one mechanism; two primary methods are pushing too hard or moving the joints improperly. One is forcing the bones together in an aggressive manner creating or causing too much compression. I think about this as squeezing the juice out of the joints. Another is moving the bones against the orientation of the joints. For example, the knee is a hinge joint. It should flex and extend with only mild internal and external rotation. If a student is uneducated in the anatomy of the joint, or overzealous, and tries to do padmasana (lotus) before she or he is ready, then structures can become damaged. Through the communication channels described here, the body will let you know that you’ve done something wrong. Unconscious toxic signals will be released to the brain, and may result in pain. This situation becomes more dire if the insult is done to the spinal joints, primarily because they are designed to protect your information superhighway.
Healthy movement, especially movement of the spine, can exponentially improve your physiology and psychology because of this stimulation of the proprioceptors, providing the most essential nutrient for survival.
Yoga developed from being a secluded meditative practice, in which the yogi’s asana arsenal consisted of a comfortable sitting pose, to a complicated system of movement and breath. The yogis of old knew that if they could minimize the noxious/nociceptive input into and within the brain they would be able to decrease the stress response and go deeper into their meditative states. They figured this out without expensive MRIs. Removing irritation or noxious stimulation from your spine with a dose of respectful, smooth, slow and steady yogic movements, such as yoga, Tai Chi , Qigong or dance will decrease your stress response and allow for a positive integration of your thoughts, feelings and emotions.
Dr. Jeremy Brook runs a chiropractic wellness center in West Los Angeles, California that caters to active lifestyle enthusiasts striving to achieve an energy efficient spine. For more information visit: spinechecker.com.
By Dr. Jeremy Brook
