The piriformis muscle is the most superior of the deep external rotators of the hip. The sciatic nerve passes underneath it and sometimes through it. Hypertonicity of the piriformis can contribute to many kinds of Low Back Pain, also known as Piriformis Syndrome. We will examine the factors that make for a hypertonic piriformis muscle so that we can have an effective treatment strategy. The most common imbalance associated with this condition is a facilitated piriformis inhibiting the ipsilateral hip internal rotators. These muscles, such as the gluteus medius, gluteus minimus, and the tensor fascia lata are prone to inhibition. This balance can easily be ascertained through the manual muscle testing protocol employed by NeuroKinetic Therapy. Release of the piriformis muscle is immediately followed by activation of the internal rotators to reprogram the dysfunctional movement pattern that has been stored in the motor control center. This change is first stored in short-term memory, so it becomes imperative for the client to perform their homework twice a day in order to convert this new functional movement pattern into long-term memory.
The piriformis is also a synergist for the gluteus maximus in extension of the hip. Problems occur when the gluteus maximus becomes inhibited, which is very common. The piriformis was not designed to carry the load of the gluteus maximus, much like a local to global muscle relationship. Furthermore, when hip flexors, such as the psoas become inhibited, the piriformis can become facilitated in this agonist/antagonist relationship. Often times the piriformis will be assisted by the quadratus lumborum ipsilaterally to compensate for an inhibited psoas. This will create a significant case of lower back pain.
Because the piriformis is an external rotator of the hip, it works with the opposite internal rotators of the hip to create ipsilateral lumbar rotation. Therefore inhibition of the contralateral internal rotators of the hip or contralateral external rotators of the hip will create facilitation of the piriformis. Pictures of these tests are in my book, “NeuroKinetic Therapy”. The piriformis also externally rotates the sacrum and can be a major contributor to sacroiliac joint dysfunction. This is often seen in a dysfunctional gait pattern where loading on the forward moving leg is compromised. The sacrum normally externally rotates during this action. Examination of the muscles that contribute to this action, including those that create lateral flexion of the spine, is crucial in unraveling this pattern. For example, the right piriformis could be inhibiting the left quadratus lumborum, left lumbar erectors, left psoas, etc.
A properly functioning piriformis muscle is crucial in maintaining a healthy low back and sacroiliac. Understanding how to assess and treat a hypertonic piriformis is crucial in resolving dysfunctional movement patterns associated with Low Back Pain and Sacroiliac Dysfunction.