I had tingling (pins/needles sensation) and numbness in legs and feet. It felt like pain shooting down the back of my legs. Rest, stretching with exercises from PT and ice helped. Must do stretching slowly. My physicial therapist said that when I was raking leaves i may have irritated the muscle with the motion of pulling the leaves toward me. But the real winner was nerve block in the piriformis muscle. The use ultra sound to guide to make sure that they hit the priorformis muscle. They said the pirformis muscle was spasms against the sciatica nerve. They did not inject medication in the SI joint. It is sharp pain down the leg.