Just like with the posterior pelvic tilt, the anterior pelvic tilt is named because you are tilting your pelvis forward, or anterior. This creates more of an arch in your back causing your buttocks to stick out more.
Most people need more anterior tilt to their pelvis. People usually like to slouch back onto their tail bone as they sit... it is just easier! As discussed in the proper sitting page, you probably need to lean more forward to get your weight centered over your sit bones. Sometimes this change alone can bring relief for your back pain.
Remember: Like with the posterior tilt, we are going for improved proprioception. Do all motions slowly and thoughtfully. Move with attention. Don't push into pain. Less is more here. Be really subtle, and notice everything. This will improve the connections to your brain.
It may feel "pinchy" to arch your back like this... Don't push into the pain. Just do a little at a time until you are more used to the motion. I find doing a rocking motion between anterior and posterior tilt very helpful to calm down my muscles when they start going onto spasm. It can even help decrease spasms that have already started.
Let's add the next layer - lateral pelvic tilts!
Go to Part 5 - Lateral Pelvic Tilt