The sciatic nerve innervates all muscles of the posterior thigh, leg and foot. It is as thick as a finger and is formed from the nerve roots that originate from the sacral plexus (groups of nerves) that emerge from the vertebrae between L4 and S3. It is actually two combined nerves, the tibeal nerve and common fibular nerve, which branch out in the lower thigh area and continue distally to innervate the lower leg. Sciatica often is a result of two causes: a herniated disc or piriformis syndrome.
A herniated disc can result in numbness with tingling radiating pain down the back of the leg.
Piriformis Syndrome is basically tight lateral rotators which can compress the nerve & cause pain.
The lateral rotators can be stretched with the following poses:
Uttanasana: standing forward bend with thighs parallel or internally rotated
½ Pigeon: with bent leg pelvis supported on blankets
Modified ½ pigeon with bent leg on table or low counter top
Marichyasana 3: Sit on support and twist towards bend leg
Ankle to knee: Sit on support with one leg straight or bend both legs (one or two ankles to knees)
Modified ankle to knee: sit in chair and place one ankle over other thigh. Bend forward from hips
Badha konasana: feet touching & close to groins
Tarasana: extend feet about 18-42 inches from pelvis, lean forward from hips
Please note that and an MD should be consulted if sciatica is suspected or pain persists.
Moore and Dalley (2006) Clinically Oriented Anatomy, 5th edition, Lippincott Williams & Wilkins, Baltimore, MD.
Lasater, Judith (2009). Yogabody: Anatomy, Kinesiology, and Asana. Rodmell Press, Berkeley, CA.