We have five different parts to our incredible nervous system: the brain and spinal cord (also called the central nervous system), the peripheral nerves, the enteric nervous supply and our autonomic nervous system . They are all made up of nerves that carry electrical messages around the body to control it’s various functions but each has a specific role and yoga can affect each in a different way. Last week in part one, I looked at how the nervous system, specifically the autonomic system, counters our ‘fight and flight’ responses with a calming influence during yoga.
Your Brain In Balance
Not only does our nervous system keep our blood pressure, muscle tension and pulse rate in balance but it plays a huge role in improving our actual balance too. Regardless of whether we are on our head, hands or feet (or combinations of the three during yoga), our ability to stay upright is controlled by our nervous system. There is a continuous stream of messages going from sensors in our muscles, tendons and ligaments to our brain informing it of what is going on in every part of our body.
Within a split second, the brain interprets the information and instantaneously sends messages back to our muscles to ensure that we stay where we need to be. Think about your ankle when you are in Warrior Three: your whole body is twitching to fine tune your balance in response to the information your body is sending your brain. This communication loop is called proprioception and is going on all of the time.
After suffering an injury, or as we get older, this communication loop becomes less effective and our balance and co-ordination worsens. Yoga poses exercise this skill, over time it gets better and faster and presto! Your balance and co-ordination improve. I remember a few years ago I could barely stand on one leg to put a sock on because I was so unfit that my proprioceptive system was lazy. Now I can stand on one leg in a range of yoga poses and change my footwear and in a muddy car park without ending up with a bare foot or fresh sock in a puddle!
Nervous System Aches And Pains?
Finally, there is the peripheral nervous system. This includes all the nerves leading from the edge of the brain and spine into the face, torso and limbs, and all the way to the tips of our fingers and toes. In this system we have two types of nerves: nerves that send messages to our muscles (motor nerves) and nerves that send messages to the brain (sensory nerves).
The motor nerves pass from the brain and spinal cord to the muscles and are the ones that produce the response to what the sensory nerves are feeling. The sensory nerves pass information from sensors in the body up the spinal cord and into the brain. They tell the brain about things like:
- Our environment
Imagine you burn your finger on a hot dish (sensory) you will immediately pull your finger away to prevent further damage (motor). Both motor and sensory nerves run through the limbs and round our torso in tunnels through muscles, round bones and through fascia (the connective tissues of the body).
Whenever we move, each nerve slides in it’s channels. An injury directly to the nerve or surrounding tissues will heal to leave a bit of scar tissue in the area. Built up scar tissue around a nerve can prevent it from sliding freely. Sometimes when you are in a yoga pose there will be a tug on this scar tissue round nerves and you will feel pain, pins and needles or numbness.
If this happens, there is a danger that you could be damaging that nerve and you should ease back away from the unpleasant sensation to protect it. Never push through anything that doesn’t feel like a stretch. Working in this comfortable range will help to free up the scar tissue around the nerves and you will probably find that, in time, you can move further without feeling the nasty sensations.
Really Useful Info About Flexibility
Another clever function of our nervous system is to prevent damage to one set of muscles when the ones doing the opposite movement are working. Take your legs for example, ever wondered why your teacher tells you to engage the front of your thighs in forward bends? It isn’t just to make things harder for you — honest.
When we contract the quadriceps muscle on the front of the thigh, our body automatically relaxes the hamstrings down the back of the thigh to prevent them from damage; with the added advantage that your forward bend gets deeper. This is a subconscious spinal reflex where the messages in the nerves go from one muscle up to the spinal cord then directly out to the other muscle without the brain being involved. It is called reciprocal inhibition and happens in every pair of muscles we use as we move around. The real bonus is that we can cash in on this amazing natural bit of muscle protection to deepen all sorts of poses to develop our practice.
The best part about all this, is that our bodies do all this without us knowing anything about it! Next time you are balancing in Tree Pose or feeling a bit wobbly in Crow, spare a thought for your nervous system. Maybe it’s even time to say a little ‘thank you’ to your nervous system! It could be a great intention for next practice.
I’m really looking forward to exploring the cardiovascular system with you in my next article – see you there!