Back and leg pain are both symptoms of a herniated disc. Although most people think that back pain is the only symptom, leg pain is a symptom of a specific and severe type of nerve root compression. A prolapsed disc may cause acute pain due to severe inflammation.

Back symptoms: Lower back pain can occur on one or both sides of the body, especially when sitting or bending forwards due to the amount of force placed on the discs.
 
Leg symptoms: Patients may experience pain, numbness or muscle weakness in the legs.
 
A herniated disc causes leg pain or numbness in the part of the body that is served by the affected nerve. The pain can begin at the waist and extend to the thighs, calves, feet and toes. As with the pain or numbness, muscle weakness in the legs is caused by compression of the spinal nerves.