What is Sciatica?
This is a layman’s term used to describe a common back problem and as such it is not a clinical definition of any specific condition. Sciatica is related to the sciatic nerve which is the thickest and strongest nerve in the body.
The nerve can sustain a hanging weight of 700kg (the weight of 7 adult men) before breaking. The roots of the Sciatic nerve control motory, sensory and mixed functions via the bones, muscles and skin and it divides into two sections which pass down from the spine, through the hips, into each leg.
Since none of the nerve roots correspond physiologically, different types of pain can be produced; e.g. a dull ache is felt in bone, numbness (acroparisthesia) in skin, and sharp pain in muscle – and of course these symptoms can overlap.
The Sciatic nerve is in close proximity to adjacent discs (1.2-1.5 mm) which is why so-called discongenic pain can arise. This pain however is caused by the tethering or rubbing of the nerve sleeve, and not by the discs themselves, while compression of the nerve doesn’t necessarily cause any pain.
As a result of mechanical friction affecting any of the nerve roots, the condition can become inflammatory which is extremely painful. If not treated properly this will lead to scarification in the area around the inflamed sleeve which in time would result in devascularisation (reduced blood supply to the veins).
The body reduces the supply of blood to certain veins if parts of the body are scarred and no longer require it as much as when the tissue was healthy. This process, which occurs as a result of the condition and also as a consequence of surgery, often produces referred pain along those nerves which are affected.