Sciatica is a general term that a lot of people throw around to describe their lower back pain and any pain radiating down the leg. However, there is a lot of confusion as to what sciatica really is and why people get it. Sciatica is NOT a diagnosis, but rather a symptom that can be caused by any number of different conditions. In this blog we will describe what the sciatic nerve is, some of its common causes, as well as the different ways that it can be treated.
Anatomy lesson: The Sciatic Nerve
The sciatic nerve is the largest nerve in the body. It originates in the lower back from spinal nerves L4-S3 and travels down the buttocks, back of the thigh, lower leg and foot. Sciatica occurs when the nerve is pinched or irritated, which causes pain, burning, tingling, shooting and/or numbness anywhere along its path. If you have sciatica-like symptoms, it doesn’t automatically mean the nerve is involved. Certain muscles and joints have referral patterns that mimic sciatica, but the nerve is not actually involved. For example, sacroliliac joint dysfunction can refer pain to the buttock and back of the thigh, without involvement of the nerve. Likewise, trigger points in the hamstrings, piriformis and glute muscles all have referral patterns similar to sciatica. The key to getting rid of your sciatica is finding out what is causing it.
Causes of Sciatica:
There are a number of conditions that can cause sciatica. Below we will briefly discuss the more common ones and the different treatment options for each:
- Acute Nerve Root Irritation:
Sciatica can be caused by irritation to any of the nerve roots that branch into the sciatic nerve; remember from the anatomy lesson above, the sciatic nerve originates from nerve roots L4-S3. A nerve root irritation can be caused by disc herniations, spinal stenosis, infection, tumours, or instability. It is characterized by swelling around the nerve, which will produce constant pain along that nerve root path. The goal of treatment with this condition involves improving the swelling around the nerve root, patient education, and pain control.
- Disc Herniations:
A disc herniation from any level between L4-S3 can cause symptoms of sciatica. For example, an L5 disc lesion will affect the L5-S1 nerve root, causing symptoms in the lower back, buttock, leg and foot. Treatment will generally consist of education (especially on posture), pain control, manual therapy to restore mobility and open up the space around the disc, and exercise consisting of McKenzie exercises, strengthening and posture re-education.
An instability in the lower back can be due to fractures, infection, degenerative disc disease, pregnancy, or repetitive movements into extreme ranges (ie., gymnastics, wrestling). An instability in the spine will lead to abnormal range of motion because one or more segments are no longer held together tightly. The unstable spinal levels can lead to nerve compression, which causes the sciatica. Treatment for instability will consist of pain control, education, manual therapy to address stiffness above or below the unstable segment, exercise for core stabilization and specific retraining of the muscles at the level of instability, and in some cases the use of lumbar supports/braces.
- Piriformis syndrome:
The sciatic nerve either runs through the piriformis muscle or directly under it. As such, if the piriformis muscle is irritated or tight, it can lead to sciatica as the nerve becomes impinged in the muscle. Treatment will usually focus on manual therapy to actively release the muscle and exercise to address tightness/weakness in the area.
There are many other causes of sciatica; however, this blog is meant to highlight a few common ones and stress the importance of having your sciatica assessed by a therapist instead of ‘Doctor Google’. A thorough assessment of the muscles, joints, and nerves will help find the root cause of your symptoms, which is the key to getting healthy. Not all sciatica is the same, therefore not all sciatica is treated the same. A proper diagnosis will lead to the most effective treatment protocol.