Our hips are one of the most mobile joints of the body thanks to their ‘ball and socket’ design. One of the primary movements of the hips is rotation. External (or lateral) rotation is facilitated by numerous muscles including the Piriformis muscle. This muscle has an interesting anatomical setup that requires some playful and purposeful isolation into order to functionally target it when stretching.
The Piriformis muscle originates at the anterior surface of the sacrum between and laterally to the anterior sacral foramina. It crosses the hip joint to insert on the upper thigh bone (femur) on the superior boundary of the greater trochanter. As the pelvis is fixed, this muscle contracts and draws the upper trochanter (and therefore the femur) back into external rotation.
External rotation is a fundamental action of the hip in many activities including basic walking and running patterns (gait). With chronic overuse, poor posture, or other musculoskeletal dysfunction, the Piriformis along with other hip rotators and stabilizers can become tight and/or inflamed. Traveling underneath the Piriformis muscle is the sciatic nerve (15% of people have the sciatic nerve passing directly through the Piriformis muscle). If the Piriformis becomes overly tight or inflamed, it can impinge on the sciatic nerve (called Piriformis syndrome) presenting similar symptoms as sciatica: numbness, tingling, or burning pain in the hip or down the back of the thigh.
Besides providing movement to the hips, the Piriformis muscle also offers stability to the sacroiliac joint by fascially connecting to the sacrotuberous ligament. While offering support, the Piriformis can also be problematic. If this muscle is enduring chronic tension, this tension drag can act on the sacrotuberous ligament that could possibly destabilize the SI joint. Hence, a balance of having supportive tension as well as mobility in this muscle is optimum.
Overall, the Piriformis muscle benefits from regular, therapeutic stretching and mindful hip opening postures. However, there are some nuances required to best isolate this muscle. When the Piriformis muscle is stretched, it is typically done so with the hips in a flexed position. When the hips flex, the angle of tension or pull from the Piriformis shifts. Instead of being an external rotator (as when standing and hips extended), the Piriformis becomes an internal rotator. Therefore, when the hips are flexed, we first need some degree of EXTERNAL rotation of the hip along with some hip abduction to properly stretch this muscle.
The second component to focus on is isolation of attachment points. In postures like Reverse Pigeon pose, I often see people pulling their thighs close into the body allowing their lower spine (trunk) to flex (you will see how their pelvis tilts away from the ground). This lifting of the pelvis means they have allowed the origin of the muscle (sacrum) to move with the insertion (greater trochanter) – we want those two points moving AWAY from each other. Therefore, in order to isolate hip flexion and move those attachment points effectively away from each other, we need to engage in spinal extension of the lumbar region to resist spinal flexion.
Interesting, when you properly isolate the hips with spinal extension in postures like Reverse Pigeon, you will discover that you come into the stretch far more quick and require less ‘range of movement’ to get to the edge of the stretch. The visual depth of the posture certainly isn’t as grand, but the functional isolation is greatly enhanced. Alas, the mantra ‘less is more’ comes into play. Once isolated, explore the abduction and external rotation lines – move the affected thigh away from you – move it slightly side to side. You will likely find how very subtle alignment shifts can greatly enhance isolation and move into different muscle fiber lines.