What is the Sciatic Nerve? Can it be Compressed?
We’ll start with the sciatic nerve itself and where it comes from. As you might have read, a number of nerves leave your spine and join together to form the sciatic nerve. The sciatic nerve runs from your lower back through your hip and buttock region down the back of your thigh before branching off towards your foot.
Now, in very rare cases a problem can occur at the roots of the sciatic nerve (the roots being where the nerve exits the spine). This problem might be that the nerve has become compressed by a herniated disc or in even rarer cases a malignancy or infection. This compression causes the nerve to become irritated, triggering inflammation and sometimes severe pain down the back of the leg below the knee, along the course of the nerve.
The Good News
The good news is that a disc issue such as a bulging disc, slipped disc or herniated disc is very rarely the cause of a person’s radiating pain down their leg. There is a lot of misinformation spread about the intervertebral discs in our spine. They are often portrayed as fragile structures that are waiting to burst upon an awkward movement, when in reality, they are incredibly robust strong structures that can withstand huge amounts of force.
What is so confusing about sciatica?
Today sciatica is used more as an umbrella term. The term ‘sciatica’ is often used by people who have experienced an episode of back pain along with pain that travels down the back of their leg. This is not technically correct. In the vast majority of cases, this should be called referred pain, not sciatica. ‘True sciatica’, also known as radicular pain is due to a compression or irritation at the nerve root.
Simply put, low back pain and referred pain down the leg is common but this is rarely due to a compression at the nerve root.
So, if my Sciatic nerve is not compressed by a Disc, What is causing the pain running down my Leg?
As mentioned, it is very common for people to experience low back pain and pain running down from their buttock into the back of their leg. This pain is most commonly experienced due to something called somatic referred pain.
Let’s briefly explain referred pain. Referred pain is when the pain you experience in one part of your body (down your leg in this case) is caused by the signal of pain in another part of your body (lower back muscles).
We have a vast network of nerves throughout our body that make up the nervous system. The muscles in our lower back can often become tight, sore and even go into spasm. When this happens, our nerves carry the signal of pain from the muscles to our spinal cord and up to the brain. However, our vast network of nerves work closely together and there is very often communication between nerves in adjacent areas. Therefore, there is communication of the painful stimulus between the nerves around our back muscles and the nerves that travel down to supply the muscles and skin in our legs.
Other common examples of referred pain include people with hip arthritis that experience pain in their knee, or people with neck pain that begin to feel pain in their shoulder region.
How Can Exercise Help My Back and Leg Pain?
Firstly, when you exercise you allow your back and leg muscles to contract and relax. In this way exercise can help release the tension in your back muscles. Secondly exercise encourages blood flow and oxygen to the nervous tissue. This helps to calm your nervous system down and reduce the constant signal of pain being sent from your muscles.
What Else Could Be Causing The Pain Down My Leg?
There is a number of other issues that can cause people to experience pain down the back of their leg. These issues range from tendon issues such as the hamstring tendon that inserts into the back of your pelvis, to issues around the hip joint and muscles. These other possible causes will be ruled out during your physiotherapy assessment.
When Does Sciatica Require Surgery?
As mentioned there are very rare cases when a problem is occuring at the nerve root. This problem may be due to compression of the sciatic nerve roots by a herniated disc. People that experience severe leg pain from this cause can experience some shorter-term relief with surgical intervention. A suitable candidate for such a surgery may include someone with all of the following:
- Very severe raging leg pain that is far worse than their back pain
- Pain is constant and unrelenting
- Sharp shooting pain
- Experience their symptoms below the knee
- Severe numb patches down their leg
- Severe weakness in their legs
- No relief from exercise
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