The truth about sports, nutrition and pain!

Posts tagged ‘nociceptors’

Why does pain move?

I have already talked about pain numerous times, in fact three times (pain part 1,2,3), but this is a subject that people have a hard time understanding. So, I will do one more post to try to clarify things. The most important thing about pain that people should know is that pain is an output of the brain and that pain does NOT EQUAL TISSUE DAMAGE (1-5). It sounds almost crazy and scary but it is true. That is why sometimes you see people with lots of arthritis that have no pain and other people who have very little arthritis and have lots of pain. Pain depends on the situation, I will give an example: Imagine a soldier at war and a professional soccer player at a match, and they both experience the same devastating knee injury. For those two people the significance of their injury is going to mean two completely things. For the soldier it means he can get the hell out of there and go home, for the soccer player it means good-bye to his professional career and maybe even income. Take a wild guess and think who is going to experience more pain??

But anyway, let us get back to the topic at hand and try to clarify why pain moves. Pain is basically controlled by the nervous system, so imagine something happens to your back,  ¨nociceptors¨will send  this information to your spine and from there to the brain. Now, let us suppose this ¨injury¨ keeps bothering you for a while, and these ¨nociceptors¨ will be firing away 24/7 during this whole time. At the end, the pain becomes centralized. Now, this is where it gets interesting. Your spine is also receiving at the same time information from all the different parts of the body. Once the original pain has become ¨centralized¨, the spine can sometimes make an error and get confused with all the different types of information that it is receiving from its nerves (6). This confusion can lead to the pain moving from one place to another. Now, when this happens it doesn´t mean that you have injured yourself in a new area,  it just means that your central nervous system has made an error in its processing of the information.


Hope you liked it.


  1. Flor H, Nikolajse Li, Stachelin Jensen T. Phantom limb pain: a case of maladaptive CNS plasticity.Nat Rev Neuroscience 2006 Nov;7(11):873-81.
  2. Flor H, Braum C, Elber T, BIlbaumer N. Extensive reorganization of primary somatosensory cortex in chronic back pain patients. Neuroscience 1997: March 7.224(1)5-8.
  3. Ren K, Dubner R. Central nervous system plasticity and persistent pain. J Orofac. Pain.1999.Summer.13(3):155-63.
  4. Kim S, Lee Hoo T, Lim Mee S. Prevalence of Disc Degeneration in Asymptomatic Korean Subjects. Part 1: Lumbar Spine. Journal of Korean Neutrosurgical Society 2013 January;53(1): 31-8.
  5. Kendrick D, Fielding K, Bentler E, Kerslake R, Miller P, Pringle M. Radiography of the lumbar spine in primary care patients with low back pain: Randomized controlled trial. BMJ 2001;322:400-05.
  6. Hargrove T. A guide to better movement.  Better movement 2014. pg 101-4.


THE BOSS -The Central Nervous System-

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.





  1. Ratey, Hagerman . Spark: The Revolutionary New Science of Exercise and the Brain. 2008
  2. Weppler et al. Increasing muscle extensibility: a matter of increasing length or modifying sensation? Phys Ther. 2010 Mar; 90(3):438-49
  3. Noakes. Fatique is a brain derived emotion that regulates the exercise behavior to ensure protection of whole body homeostasis. Front Physiol. 2012; 3: 82.
  4. Moseley and Butler. Explain pain. 2013
  5. Hodges P. Moving differently in pain: a new theory to explain the adaptation to pain. Pain. 2011 Mar; 152: S90-8






Pain part 1

It´s a complex and mysterious thing. I always thought that pain came from an injury or damage caused by misaligned joints, weak and tight muscles, ruptured disks, bad posture and so on. But recent studies have shown that to be false. Pain is produced 100% of the time in the brain and depending on the situation, your well being, your emotions and a thousand other things, that pain is going to be more intense or less intense. In some situations you may have an injury and not even feel the pain.!!….surprised? So am I, so let´s try to explain it.

Pain before was often thought of as a reflex mechanism, meaning that when you got hurt, pain receptors would send signals to the brain and we would sense that pain. But it doesn´t really work that way. What we have are called ¨nociceptors¨, and these nociceptors are similar to other receptors that sense pressure and temperature. The only difference being, that you need a bigger stimulus to activate these ¨nociceptors¨.

So when these nociceptors are activated they send warning signals to your brain and it´s up to your brain to decide whether it is a real danger or not. So you will not feel pain unless and until the brain believes that there is a threat to the body.

Pain can be divided into 2 different types of pain:

  1. Acute pain is the one you experience after a broken bone, a cut, a surgery, a burn, and such pain usually goes away when the underlying injury has been treated or healed. It might last for a few seconds, hours, weeks or, at the most, 3-6 months, which is the time it takes to heal and remodel connective tissue.
  2. But in a few people, even after the tissues had enough time to heal, pain persists for years, this is called chronic pain.

This could be a little complicated, so let´s stop here, analyze the information and take a look at a couple of videos that I think will help you understand the concept of pain better.  The second video is about Lorimer Losley. He is the author of ¨Explaining Pain¨, a great book I recommend.

I will stop here for today and continue next time with the second part of pain, where I will talk about how to treat pain. Hope I made you think.

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