For some, it’s a numb foot. Others, it’s debilitating pain that radiates down the back of the leg. Whether it shoots into your hip or down your entire leg, you’re most likely suffering from “sciatica.”
Sciatica is a fairly vague term. By the most literal definition sciatica is the inflammation of the sciatic nerve. The diagnosis seems to be a “catch all” term for pain traveling down the leg. And while the term sciatica is fairly common, the cause for nerve irritation can vary widely. Each “cause” of sciatica has a varied treatment path–which highlights the importance of understanding the “why” behind your pain.
What does sciatica look like?
The sciatic nerve is large nerve that runs from the low back, into the buttock, down the back of the thigh, and branches off down to the lower leg. If the nerve gets pinched, compressed, or tensed anywhere along the long path from the low back to the foot. It may sound a little fishy at first, but your pain may refer away from the injury site. It’s not uncommon for a patient to have a low back injury that present as symptoms elsewhere (i.e. the calf). Sciatica can present itself as pain, numbness or tingling, and leg weakness. Lets dive deeper into what causes sciatica with three common causes.
#1. Disc Herniations
An estimated 90% of the seven million annual cases of sciatica in the United States are caused from a lumbar disc pressing on the sciatic nerve (Koes et. AL). The discs in our spine provide cushion and act as a shock absorber as we move. If the disc “bugles” or “herniates” it can compress a nerve as it exits the spinal canal. That nerve root compression can cause significant pain, weakness, or numbness any along any point of the nerve path.
#2. Disc Degeneration
Another common cause for “sciatica” includes degenerative changes at the spine leading to spinal stenosis. Spinal stenosis is a diagnosis that results in narrowing of the canal where nerves exit the spine. This narrowing of disc space can result in crowding of the spinal nerves or even compression. Crowding or compression of any nerve root, not just the sciatic nerve, can cause referral pain along the path of the nerve.
#3. Nerve Entrapment
Sciatica can also arise from a “pinch” or entrapment of the nerve. This can occur anywhere along the path of the nerve–not just at the spine. You may have heard of your piriformis muscle? This deep muscle of the buttock lays a roof for the sciatic nerve as it passes through the hip and down the leg. In fact, the sciatic nerve punctures through this muscle in a small percentage of the population.
Piriformis tightness is one example of a non-spine-related cause for sciatica. This and other structures of the leg may cause pinching or tensing of the nerve, ultimately leading to buttock or radiating leg pain.
How to prevent sciatica
The key to preventing any spine injury is a stable core, flexible and strong hips, along with proper body mechanics. Unfortunately, having all the prerequisites is uncommon. Those between 45-64 years of age, who smoke, and with mental stress all have high risk for sciatica. Moreover, a job that requires excessive bending, lifting, twisting, or prolonged sitting increase the likelihood of having sciatica (Koes et, al). That seems a little disheartening, doesn’t it? Those risk factors are blanketed by nearly all occupations.
While you may not have control over your occupational hazards, your posture, lifting mechanics, strength, and flexibility are within your control. For more detailed descriptions of proper lifting techniques check out this article and this article.
It’s important that the diagnosis of “sciatica” doesn’t give you the “why.” There are many causes as seen above. Remember, strong, flexible hips and great body mechanics are best for prevention. Take five minutes out of your day for some healthy stretching and strengthening. Your body will thank you for it!
Koes, B. W., M. W. Tudler, and W. C. Peul. “Diagnosis and Treatment of Sciatica.” BJM 334 (2007): 1313-317. Web.