Fascia is just like magic....It provides layers of connective tissue that cover all of our muscles, joints, bones and organs within the body and basically holds us together! Deeper than this however, it provides a connective web around the whole body. I've written about it previously as being a bit like the dividing segments you find in an orange, but it's a bit more complicated than that in reality, with the layers that make it up providing an interconnecting web of tissue in the body, connecting the least likely bits together (back of the pelvis with tissue in and around the jaw!).
Between all these layers sit little channels, almost like rivers and valleys, for important cellular fluids and energy (or qi in Chinese medicine) to travel around the body. In yin yoga, through longer held postures that work deep into the connective tissues, we work to free up the flow of energy along these channels (or meridians) to create optimal health in the body's organs and cellular and nervous system.
A book that I absolutely love and recommend that helps provide the 'science bit' to understanding this better, as well as giving a perspective on Chinese medicine and how acupuncture works is the brilliant 'The Spark in the Machine' by Dr. Daniel Keown (who is actually based in Kent in Tunbridge Wells). It can have some challenging medical concepts in places (for me anyway!) but overall provides many 'lightbulb' moments about how the body works for anyone who has a greater interest in this area.
One of my favourite paragraph's is a description of the lungs; Daniel says: 'The lungs are like an upside-down tree with leaves of the finest gossamer, bathing in a chest full not of air but of gently wafted blood. It's a slightly crazy visualisation because we tend to have the idea of the lungs as solid, but the material of the lungs is so fine that it is blood and air, not lungs, that makes up most of the chest. When the lungs collapse they occupy no more than a fist-sized space.'
A regular yin yoga practice (I teach a combination of yin and yang yoga) can have a beneficial impact on the whole body as well as the mind, and if you wanted to understand further as to why, this book is a great place that helps all the pieces of the puzzle fit together.