What is piriformis syndrome?
Piriformis syndrome is caused by impingement of a large nerve called the sciatic nerve as it traverses under the piriformis muscle. The sciatic nerve starts from nerve roots in the back, and extends through the buttocks area and down the lower extremities. The impingement of the nerve causes pain to the buttocks and or hip, and may cause symptoms such as numbness or tingling, pain radiating down the leg, weakness in the leg of the side affected, difficulty with ambulation, among others.
Why does piriformis syndrome occur?
Sciatica occurs due to the anatomy of the muscles and the sciatic nerve. The piriformis originates from the sacrum to the greater trochanter. In over 90% of the population, the sciatic nerve travels just beneath the piriformis muscle. When the piriformis muscle experiences spasm, any kind of overuse, or direct pressure-such as sitting for long periods of time, the sciatic nerve can be compressed and cause pain and other symptoms. The piriformis muscle is responsible for external rotation, flexion of the hip, and some abduction. Therefore, spasm, overuse, or enlargement of the piriformis muscle due to inflammation can cause pain.
Who is at risk for piriformis syndrome?
Although some people are at higher risk of sciatica simply due to their anatomy, there are others that are also at higher risk. These populations include those with degenerative arthritis of the back, any disc diseases of the lumbar back, trauma or injury, obesity, prolonged sitting or a sedentary lifestyle, and diabetes.
What are some diagnostic tools?
Patients will often complain of pain just over the piriformis muscle, and palpation in this area can illicit pain. There are a number of exam tests that physicians can use to aid in their diagnosis of piriformis syndrome. These tests are known as Lasegue, Freiberg, and Pace signs. The Lasegue sign produces pain over piriformis muscle when pressure applied to the muscle while the hip is flexed and knee is extended. The Freiberg sign elicits pain while the physician internally rotates the patients hip. The Pace sign pain occurs with hip flexion, adduction of hip, and internal rotation of hip, known as the acronym FADIR. Another test, the Beatty test can be performed with the patient lying down on the opposite side of the affected leg, then lifts the affected leg towards the ceiling. If pain is reproduced, then the test is considered positive.
Will imaging show that I have piriformis syndrome?
Unfortunately, imaging such as XRAY, MRI, or ultrasound will demonstrate limited findings. Thickening of the piriformis muscle or frank sciatic impingement may be seen, but this is not a reliable method in diagnosing sciatica. Ultrasound does give the advantage of doing a dynamic real time evaluation where nerve impingement during functional movement can be assessed.
How can we treat piriformis syndrome?
NSAIDS, muscle relaxers, local steroid injections, OMT techniques, and physical therapy are the treatment for piriformis syndrome. Here at SPARCC, we use physical therapy as a very useful tool. The goal of physical therapy is not only to strengthen the muscles surrounding the piriformis muscle, but to strengthen the core, pelvic, and abdominal muscles to provide more support for the back. There are also many stretches that patients can perform at home for relief. Many stretches involve externally rotating the hip to stretch the piriformis muscle and to decrease the spasm. Some exercises that can provide relief are the reclining pigeon pose, forward pigeon pose, standing hamstring stretch, and knee to opposite shoulder. Examples of performance can be seen with images below.
By Stephanie Farmand and Mo Mortazavi, MD
References
Boyajian-O’Neill LA, McClain RL, Coleman MK, Thomas PP. Diagnosis and Management of Piriformis Syndrome: An Osteopathic Approach. J Am Osteopath Assoc 2008;108(11):657–664.
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“Prenatal Yoga – Pigeon Pose (Kapotasana).” BabyMed.com. N.p., 10 Oct. 2017. Web. 22 Jan. 2018.
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