Despite being around for over 3 thousand years, acupuncture is still having to fight its way to be seen as a reputable medicine here in the west. Some people dismiss it as a placebo, while others see it as nothing more than voodoo or some sort of magic. Yet acupuncture is steeped in science and it is only in recent years, as our understanding of how the human body works and medical technology have developed, that we are finally beginning to understand the ‘how’. This is just a glimpse at what we are now discovering.

We all know how bodies look from the outside but what about how our brain views it from the inside? Meet the cortical humunculus (Fig 1). The cortical homunculus represents the importance of various parts of your body as seen by your brain (Fig. 2). There are two types of cortical homunculi: sensory and motor, and the amount of brain devoted to any given body region is proportional to how richly innervated (lots of nerve endings) that region is, not to the body region’s physical size. Areas of the body with greater or more complex sensory or motor connections are represented as larger in the homunculus, those with fewer or less complex connections are represented as smaller. The resulting image is that of a distorted human body, with disproportionately huge hands, lips, and face.

All of these nerves are then arranged in the body in a complex but highly organised way. They radiate out from the spinal column in branches with a single nerve root innervating a specific area of the body. These areas can then be mapped on the body into what are called dermatomes (Fig. 3). A dermatome is defined as an area of skin that is mainly supplied by a single spinal nerve.

It is this wonderful arrangement of our nerves and how they connect to our brain that facilitates acupuncture and allows me to put a needle in your hand to affect your shoulder or your lower back or your other hand. Sometimes we chose acupuncture points based on the body’s dermatomes, other times we chose points based on a reaction area in the brain. For example, there’s a couple of wonderful points on the lower leg that affect the teeth! We also use the opposite side of the body to treat the diseased side too, another words we use the right to treat the left and vice versa. This is because the brain reverses everything, except smell!

So, next time you come to me with a pain in your left hip and I put a needle in your right shoulder or hand, know that I haven’t lost my marbles, I’m just tapping into the wonderful and extremely powerful world of your nervous system. That is where the magic lies.