Most physical therapists (PTs) are very interested and willing to teach and educate their patients about the cause and treatment of low back pain. Don't hesitate to ask your PT again about the goals and treatment plan for you. In the meantime we hope this explanation will help.
Back pain that goes into the buttocks and down the leg is often called sciatica. There are many causes of sciatica. One of the most common is a disc pushing out of its space and pressing on the sciatic nerve.
The goal in physical therapy is to help the patient keep the pain in the center of the low back area without going down the leg. This is called centralization. It's a sign that the movement is helping the disc move back where it belongs. Positions and movements that cause pain to go down the leg are avoided. It's as simple as that!