Hi, thanks for writing to HCM. If you have pain originating from the back and radiating down the leg (on backside of leg) into the ankle & feet is most likely to be Sciatica and is due to a protruded lumbar disc causing compression over the nerve root. An MRI scan of the lumbar spine will help in establishing the diagnosis. In the meantime, * Avoid excessive forward bending * Take adequate rest * Use analgesics & muscle relaxants as needed Consult an orthopedic surgeon for further evaluation and management. Hope this information is helpful. Good day