Stretching the piriformis can be a very effective way of diminishing the compression, and therefore irritation of the nerve. Pictured to the left is a very common stretch given as treatment to relieve sciatica.
Piriformis Stretch Refined
Picture on the left: The half cylinder and block supports my shoulders and head to allow me to rest with a neutral spine, with my ribs down and a level pelvis. Due to my current tension patterns, I also have to support my lumbar area with a rolled yoga mat so I can comfortably attain neutral pelvis (pubis and ASIS level).
Middle picture: I place my left leg straight on the wall and cross my right leg over the left, making sure not to tilt the pelvis. Picture on the right: I begin to slide my heel down the wall and stop when I feel that I am at my resistance barrier, or my pelvis begins to shift. Hold at least one minute and repeat on the other side. If you can tolerate the stretch stay longer, up to 5 minutes on each side.
Even if you don't have sciatica, this is a wonderful stretch to open the hips, and allow more freedom to your pelvis! Enjoy!