I think we can all relate to the words tightness, rigidity, strain, stress, anxiety and pressure when we think about muscular tension. The paradox of tension however, is that we need it in order to exist. If muscles, ligaments, tendons and fascia were not able to hold tension, we would not be able to move! But did you know that your brain controls the amount of tension in your body?
Good and bad tension
The primary motor cortex (M1) is one of the principal brain areas involved in motor function. M1 is located in the frontal lobe of the brain, along a bump called the precentral gyrus. The role of the primary motor cortex is to generate neural impulses that control the execution of movement. Signals from M1 cross the bodies midline to activate skeletal muscles on the opposite side of the body, so the left hemisphere of the brain controls the right side of the body, and the right hemisphere controls the left side of the body. Every part of the body is represented in the primary motor cortex, and these representations are arranged somatotopically — the foot is next to the leg which is next to the trunk which is next to the arm and the hand and so on. The amount of brain matter devoted to any particular body part represents the amount of control that the primary motor cortex has over that body part, so a lot of cortical space is required to control the complex movements of the hand and fingers, and these body parts have larger representations in M1 than the trunk or legs, whose muscle patterns are relatively simple.
The problems with tension come when we have too much of it, and in today's fast-paced, pressured world, almost everyone suffers from muscular-skeletal pain at some time or another. This often creeps up on us as a result of poor repetitive movement; not enough movement, or as a result of being under stress. Chronic stress (read more about this in my earlier post here) leads your brain to forget to release tension when muscular contractions are no longer needed. So your jaw might remain tight even though you are not chewing food or your shoulders stay tight when you are not lifting. This is the kind of tension we don't want to have.
There are some 1,030 skeletal muscles in your body, making up almost half your body weight. When you perceive an intensely stressful event, these muscles immediately contract in order to prepare you for the 'fight or flight' response. It is easy to see therefore, how chronic tension can develop if nerve impulses 'to contract' are constantly being generated. These neural impulses are transmitted to the brain along sensory control fibres. When the neural impulses enter the brain, complex central nervous system events result in the generation of additional neural impulses which then return to the muscles along motor control fibres. When the motor neural impulses from the brain reach the muscles there is further muscular contraction, resulting in new volleys of neural impulses being directed to and from the brain. This muscle-brain-muscle circuit can become stick in a continuous condition of over-reaction which can lead to the development of a chronic state of tension throughout the body.
Even worse, being under stress leads your brain to contract muscles of your body that it doesn't need to activate for particular tasks. When you are working on solving a problem, you may tense your forehead even though the frontalis muscle involved can't do any thinking! This is dysponesis - a misuse and waste of energy. Prolonged contractions of the skeletal muscles may contribute to high blood pressure, a heart attack, a rapid heart beat, gastrointestinal problems or colitis. Feeling pain is a primary reaction, often occurring in the form of a headache, backache, shoulder ache etc.,
Can you force a muscle to relax?
Many of us think that we should innately know how to relax and let go of tension, but the truth is that learning how to let go of tension is a process of learning. Trying to force your body to relax is almost impossible - the harder you try, the less it works. That is one of the reasons why having too much tension is so complicated to sort out - there isn't one simple off switch we can flick. A better way is to allow your muscles to turn off by teaching it not to send those 'tense' messages except when they are truly needed. If you suffer from chronic tension, however, your brain has long forgotten how to turn off those chronically tense muscles.
The exact mechanics of what happens as muscle fibers tighten into a spasm of pain are not totally clear, but mild tension can easily build into a knot of excruciating pain in a short time. There are several competing theories and no conclusive evidence for any one of them; several may be true at once because there are multiple physiological routes to muscle spasm. One of the better documented assertions holds that when a muscle is tightened the tension slows blood flow. Normally, blood washes away the metabolic byproducts of activity, but if the muscle stays tense, it becomes oxygen-starved and metabolites, like lactic acid, build up. The pain receptors in the muscles are sensitive both to shortening of the fibres and to a buildup of metabolites. When these receptors detect such conditions, they send a message of pain to the brain.
Another theory holds that muscular tension is the product of poor lubrication between your body's many different tissues. When continual tension or an awkward position causes a tendon, for example, to rub and press against a muscle, the resulting friction irritates the tissue. Yet another cause of muscle spasm is simply sitting still. Blood flow decreases to muscles that are unused, and with the blood supply cut off, a condition known as anoxia, (oxygen starvation), can set in, leading the muscle to spasm. The agony of a spasm is, paradoxically, your body's attempt to care for itself.
How bodywork can help
Therapies which actively involve stimulating the nervous system, such as massage, can really help to address tension and provide a means for the brain to let go of chronic tension or and the body to let go of any patterns of holding it has developed. Focused, therapeutic touch is an incredibly powerful medium through which to develop more self-awareness, and in doing so, the brain can effectively learn how to let go of unwanted muscular tension. By kneading, stroking and manipulating the soft tissues of the body we are able to provide direct neurological stimulation which feeds into the feedback loop created by the nervous system and the brain. So when we touch another persons body, we are not physically making tight muscles softer, but providing a stimulus which is sensed and responded to. I always think of it in terms of making the brain aware that there's something not quite right that we would like sorted out!
There are of course, other ways to help to reduce muscular tension, including using heat and exercise. Using more than one modality is not only sensible if we want to keep tension at bay, it also provides us with a set of tools that we can use throughout our lives to keep our bodies in balance. Regular massage, learning how to do myofascial release and trigger point work using a tennis ball, using epsom salts, learning how to breathe well and how to switch off are all important. Next time you go for a massage do take a moment to remember that your therapist isn't physically taking tension out of your body, but bringing awareness to what is present in order to allow your body to perform its own adjustments. If you have regular massage your nervous system and brain will learn how to let go, and you will find that even the most chronic tension can be eased.