Although Sciatica is often mistakenly considered a unique form of disease, it is a set of symptoms that can have pathological causes of different nature. Sciatica is in fact in the sensation of pain due to compression of a lumbar spinal nerve root or to the inflammation of the sciatic nerve. The sciatic nerve, originating from the sacral plexus, is the longest of the human organism and innervates, through its branches, the anterior and posterior muscles of thigh and leg.