There are many causes of sciatica. The term sciatica describes irritation of the sciatic nerve and this may occur any where along the course of the sciatic nerve. The sciatic nerve originates from the sacral plexus. The sciatic nerve may be trapped by a lumbar disc prolapse causing compression at the nerve root, or it may be compressed more peripherally by the piriformis, a muscle that lies deep in the buttock. It may occur after prolonged squatting, immobility, or fractures or dislocation of the hip joint. Osteopathic treatment involves identifying the cause and trying to release the pressure on the nerve by improving range of motion, relaxing soft tissues and taking the strain off the structures involved.