Most people know that the central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord, and that is about it. But most people don´t know the importance of it and how it affects us in things like dealing with pain, strength, flexibility and a thousand other things (1-4). Let me explain.
Most of the information the body gets from our nerves arrives at our CNS and the CNS is going to decide what to do with that information. So for example, when you cut yourself in the hand, that is going to activate nociceptors that are going to reach your CNS. Your CNS will decide what to do with that information, so it could either ignore it or produce an ¨ouput¨ like pain (4). If you don´t believe me, just try to remember the times you have had a ¨black and blue¨and didn´t remember where that came from. You see, pain is an output of the brain to try to protect us, but if the brain decides for whatever reason (a lion chasing us down the street) that pain is not good, it is going to ignore that and concentrate itself on more important things. So, always remember that pain does not equal tissue damage and that pain is an output of the brain.
So, what about flexibility or stiffness? Well, recent studies have shown that that is probably controlled by the CNS also (2-3). You see, excess flexibility creates the threat of injury. So to control this the CNS sends information to stiffen the muscle. When we stretch and gain flexibility we aren´t stretching the muscle (although it feels like it), instead what we are doing is sending information to the brain, saying ¨hey, it is ok, the movement is under control and is not going to produce any harm, could you loosen up a little?¨
The same thing can be said about strength and fatigue. Also, when we go to the massage therapist or physical therapist and they say we have a ¨knot¨ and that is producing your pain and that they are going to take it away. Well, they probably don´t take it away, what they are doing is sending information to the CNS and if the CNS decides that what they are doing is ¨nice¨ and ¨effective¨, it will send down commands for the muscle to relax but if the CNS doesn´t like the ¨information¨ that it is receiving, the treatment will probably not work.
The brain is the real boss in our body. We have to embrace it, protect it and take care of it. One way to do it is exercise. Even if it´s mindless! And when we warm-up to exercise, remember to warm up the CNS also. One easy way to do it is imagining beforehand the movement you are going to practice, studies have shown that it will help (1).
Until next time.
- Ratey, Hagerman . Spark: The Revolutionary New Science of Exercise and the Brain. 2008
- Weppler et al. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther. 2010 Mar; 90(3):438-49
- Noakes. Fatique is a brain derived emotion that regulates the exercise behavior to ensure protection of whole body homeostasis. Front Physiol. 2012; 3: 82.
- Moseley and Butler. Explain pain. 2013
- Hodges P. Moving differently in pain: a new theory to explain the adaptation to pain. Pain. 2011 Mar; 152: S90-8