Common causes are the "disc problems," poor alignment, tightness of the piriformis muscle deep in the buttocks, and problems with the sacroiliac joints.
Sciatica also causes numbness, tingling, and/or weakess in the legs. Chiropractic care focuses on the cause of the sciatica to determine the proper care to alleviate it.
See our page on RickJardon.com for a video from the Doc himself. Also available is an interactive video from SpineHealth.com
Please watch the below video on sciatica.