Low back pain frequently results from poor posture, muscle sprain, lack of muscle tone and strength. If pain is not responding to regular anelgesics and muscle relaxants, physio, then there could be something deeper inside, like a disc bulge or something pressing on the nerve. An MRI of the Spine will clarify the issue. If pain still persists then consult a Neurospine specialist.
Next Steps
Consult a Neurospine specialist.