The piriformis muscle is a flat muscle located in the gluteal region near the top of the hip joint. This muscle is important in lower body movement because it stabilizes the hip joint and lifts and rotates the thigh away from the body. This enables us to walk, shift our weight from one foot to another, and maintain balance. It is also used in sports that involve lifting and rotating the thighs.
Tight or irritated piriformis can cause pain and spasms. There are a few different exercises that will help you relieve pain from piriformis, this particular truly works for me.
Also, foam rolling the gluteal area will relieve tension in your lower back ( an area we do not foam rolling). Please, read the general instructions on how to foam rolling, here.