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What Causes Lower Back and Leg Pain?

Did you know that issues in your spine can cause you pain in different areas of your body? It’s not uncommon for problems in the spine to cause pain that radiates down the leg. In fact, one study reported that 60% of individuals that brought up back pain to their primary care physician described having both lower back and leg pain!

So how does the spine affect your legs? Let’s take a closer look.

Causes of Lower Back and Leg Pain

Lower Back And Leg Pain

Sciatica is the condition in which pain radiates from the spine down one or both legs. However, this term is used to describe the symptom the patient is experiencing, not the cause. So what causes back and leg pain, or sciatica?

The Nervous System

Our nervous system allows our brain to communicate with the rest of our body and our body to communicate with the brain. This path of communication is how we “tell” our muscles to move. It’s also how our body “tells” our brain when we feel sensations like cold, sharp, soft, etc.

A primary function of the spine is to protect the spinal nerves that connect the brain to the rest of the body. Branching off the spinal nerves, the median, radial and ulnar nerves run down our arms. In the lower (lumbar) region of the spine, the sciatic nerves branch off from the spinal nerve and run down our legs. Nerves continue to branch off into smaller and smaller nerves and finally terminate in tiny nerve endings. This entire network of nerves in our body is called the nervous system.

Compression or Pinching of Nerves

Because nerves are used to feel sensations, they are also extremely sensitive. Therefore, pressure or pinching of nerves creates the sensation of extreme pain. When spinal nerves in the lower (lumbar) region of the spine are compressed or pinched they can cause pain to radiate down the sciatic nerve of the leg(s).

The anatomy of the spine is complex. As a result, there are many things that could cause compression of the lumbar nerves and, consequently, sciatic pain.

Possible Causes of Sciatica

Disc Herniation

The discs in our spine act as small shock absorbers between the bones in the spinal column. Overtime, and as we age, these discs slowly degenerate. Disc degeneration, or an injury, could result in the outer surface of a disc becoming compromised. As a result, the inner gelatinous material of the disc can leak out into the spinal cord space and compress the spinal nerve. If this herniated disc is in the lumbar region, sciatica can result.

Spinal Stenosis

Spinal stenosis refers to a narrowing of the spinal canal. This narrowing can be caused by many things including: a bulging disc, thickened ligament on the spinal canal, an enlarged facet joint or a tumor. If the spinal canal is narrow enough to cause pressure on the spinal nerve it can result in sciatica.

Spinal Injury

Any injury to the spine which creates compression of the lumbar nerve can result in sciatica. Such injuries have been seen in car accidents and falls.

There are many causes for sciatica or lower back and leg pain. Some common treatments are physical therapy, heat therapy and the use of NSAID’s. In addition, your doctor may be able to recommend more specific treatment methods after they have diagnosed the cause of your lower back and leg pain or sciatica.



  1. https://en.wikipedia.org/wiki/Sciatica
  2. https://www.ncbi.nlm.nih.gov/pubmed/20227645
  3. http://www.innerbody.com/anatomy/nervous/arm-hand
*Please Note: Information on this site or any recommended sites should not be used as a diagnosis or a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.
Blue Distinction Center for Spine Surgery