Sciatica, more accurately termed lumbar radiculopathy, is a syndrome involving nerve root impingement and/or inflammation that has progressed enough to cause neurological symptoms (e.g. pain, numbness, paraesthesia) in the areas that are supplied by the affected nerve root(s) (Tarulli 2007). Posterior sciatica involves pain that radiates along the posterior thigh and the posterolateral aspect of the leg, and is due to an S1 or L5 radiculopathy.
Acupuncture can help relieve back pain and sciatica by:
stimulating nerves located in muscles and other tissues, which leads to release of endorphins and other neurohumoral factors, and changes the processing of pain in the brain and spinal cord (Pomeranz 1987, Zhao 2008).
reducing inflammation, by promoting release of vascular and immunomodulatory factors (Kavoussi 2007, Zijlstra 2003).
improving muscle stiffness and joint mobility by increasing local microcirculation (Komori 2009), which aids dispersal of swelling.
causing a transient change in sciatic nerve blood flow, including circulation to the cauda equine and nerve root. This response is eliminated or attenuated by administration of atropine, indicating that it occurs mainly via cholinergic nerves (Inoue 2008).
influencing the neurotrophic factor signalling system, which is important in neuropathic pain (Dong 2006).
increasing levels of serotonin and noradrenaline, which can help reduce pain and speed nerve repair (Wang 2005).
improving the conductive parameters of the sciatic nerve (Zhang 2005).
promoting regeneration of the sciatic nerve (La 2005)