Unlocking Sciatica | What are we really talking about?

“Oh man, my sciatica is acting up again”. I hear this statement a few times a week. A patient will come in and tell me that they are suffering from sciatica, as if they are providing me with a diagnosis. Sciatica refers to pain,  weakness or decreased sensation that is felt along the pathway of the sciatic nerve. This pain pathway is usually described as symptoms running through the buttock region and down the posterior (back) region of the thigh.

An important note to keep in mind concerning sciatica is that sciatica is more a description of a symptom than a diagnosis. Almost everyone has back pain at some point in their life but the origin of these symptoms can be very specific to the individual. In reality, there are a number of dysfunctions usually originating in the lumbar spine (low back) that can actually cause these symptoms. These dysfunctions create radicular pain (pain that follows the path of a specific nerve). Common dysfunctions that often produce sciatica include disc disorders, spinal stenosis, piriformis muscle syndrome, and facet joint impingement. In this article I will try and dissect each of these dysfunctions so that one day if you do start feeling that your “sciatica is acting up again”; you might be able to understand why.

I will be primarily discussing disc disorders since it is probably the most common diagnosis I see in the clinic. To use an analogy, a vertebral disc is like a jelly doughnut. The disc consists of the annulus fibrosis (the breading of the doughnut) and the nucleus pulposus (the jelly in the jelly doughnut). Symptoms caused by disc disorders are most commonly seen in 25-45 year old individuals. It is uncommon for older individuals to experience this disorder due to the fact that the fluid in the nucleus pulposus becomes harder and more fibrotic with age. Actually, an individual’s disc height can decrease with age which can cause decreased space for nerves to exit from the cord. (Dysfunctions such as this will be discussed later in this article.) Pain from a disc is most commonly caused by a strain or tear of the annulus fibrosis, a protrusion of the nucleus pulposus or of the herniated nucleus pulposus (HNP), or an extrusion of the HNP.

A strain of the annulus fibrosis is usually caused by a lifting/twisting motion. Commonly, there is no pain moving down either lower extremity and symptoms will resolve with rest, physical therapy, and modalities such as ice to reduce inflammation. A protrusion of the HNP usually occurs gradually. Often, this condition is created by prolonged positions of trunk flexion, slumped sitting, or repetitive bending movements. To understand this condition, try and visualize the front of the doughnut being pinched so that the  jelly moves to back and creates a bulging shape in the back of the doughnut. If a protrusion is large enough it can impinge on the nerve root and send pain down the lower extremities. Finally, the most severe condition is an extrusion of the HNP. Using our jelly doughnut analogy, the jelly has burst through the breading and is now leaking into the surrounding environment. Unfortunately, the surrounding environment in our body includes your spinal cord and nerve roots  originating from your spinal cord. When the HNP extrudes through the annulus pulposus it can impinge and irritate the spinal cord and/or nerve root. Common symptoms include pain, weakness, and/or numbness and tingling in the individual’s lower extremities.

Spinal stenosis is another common diagnosis for lumbar spine pain that is felt shooting down the leg. Stenosis is a term that describes a decrease in the space of the spinal canal. This decrease in space can be created for a number of reasons including but not limited to a congenitally small canal,   a HNP protrusion, and/or an osteophyte (abnormal bone growth). Unfortunately, the result of this decrease in space can be an encroachment on  structures like the spinal cord and nerve roots that are located within the canal. A common finding with spinal stenosis is that extension  movements (leaning back) are painful and are generally relieved with flexion movements (leaning forward). To put this in functional terms, standing and walking activities will be more painful than sitting and/or seated activities. Consequently, people with this condition often walk bent over to relieve the pain caused by standing upright.

Facet joint impingement is a term that describes an impingement of tissue within the facet joint at a specific level of the spine. A facet joint can best be described as a connection between the inferior and superior processes (extensions from vertebrae) of adjacent vertebrae. This condition can occur anywhere in the spine and is commonly described by the patient as a ‘locked” feeling or “my back went out on me”. These symptoms usually occur following sudden movements that can consist of extension, side-bending, and rotation. The individual suffering from this dysfunction will usually stand or sit in positions away from “locked” movements. Along the same lines, pain is often noted with movements or positions into the “locked” position. Symptoms created by this dysfunction are most commonly felt in the lumbar spine, but research has shown that neurological  symptoms, such as pain radiating down a lower extremity, are possible.

The last dysfunction we will talk about is called piriformis syndrome. In this case, symptoms can be felt in the gluteal area and down the lower extremity. This syndrome is due to an irritation created by the piriformis muscle, which is found in your gluteal region. Specifically, it originates on the sacrum and will insert into the outside of the upper thigh. There is a widely assumed theory that the sciatic nerve runs through this muscle. Studies have shown however, that this is not true for the majority of the population. This does not mean that restrictions or tightness within this muscle is unrelated to the previously mentioned symptoms. In fact, piriformis restrictions can cause referred pain in addition to entrapment of neural structures located within or in close proximity to it. As a result symptoms can be reproduced with palpation, contraction and/or stretching of this muscle.

Now there is good news and bad news concerning all of these conditions. The bad news is the treatment of these dysfunctions will not be discussed in this article. Each condition is dealt with in a very particular way and can vary significantly from one individual to another. NOW THE GOOD NEWS!!! There are people who can help. Physical therapists are trained not only to treat every individual according to their specific dysfunctions, but to teach their patients on how to alter their specific lifestyles to help eliminate and prevent further symptoms. If you do notice that you are presenting with symptoms similar to those mentioned previously, please consult with your local physical therapist. There is NO reason to live with the pain. I hope you have found this article informative and that it might help prevent you or a loved one from experiencing that “sciatica” pain for too long.

References
Saunders H.D., Saunders R: Evaluation, Treatment and Prevention of Musculoskeletal Disorders. The Saunders Group, 1995

About the Author | Adam Smith PT,OCS graduated from the Medical University of South Carolina in 2003, where he received a Master of Rehabilitation Sciences-Physical Therapy. In 2003 Adam received the American Physical Therapy’s Association’s (APTA’s) Mary McMillan Award, the highest award given to a physical therapy student. In 2004 he participated in Kaiser Permenente’s Orthopaedic Physical Therapy Residency and in 2005 obtained Orthopaedic Clinical Specialist status.. Adam is presently acting as the Chair of the Membership Committee for the APTA’s Orthopaedic Section. Adam is a native of Long Island, NY and moved to Los Angeles in January 2004. (OCS).