Do you sometimes feel a deep pain in your buttocks while walking or running?
This might be pain from a muscle there called the Piriformis muscle. This muscle is responsible for rotation of your hip, but it is also a strong stabilizer and assistant to your low back. If you suffer from any kind of back pain, often the piriformis will get tight because it's trying to help your lower back and support it. However, this tightness can be a real pain in the butt!