Why does sciatica affect one leg? The vast majority of leg symptoms only affect one leg. Why is this? It goes back to flaws in human anatomy. There is a ligament that runs down the length of the spine and its job is to separate the discs from the spinal cord. It is called the Posterior Longitudinal Ligament (PLL). It is a very strong ligament; however, when it gets to the lumbar spine it becomes more narrow. This is unfortunate because this happens to be where the forces of leverage on the spine are most concentrated. This is why the lower three discs in the spine are the most common to injure. Equally as unfortunate…this is where the nerves to the legs start.
When a person bends and twists, strong forces push the lowest discs to the side, which is where the PLL is thin. This can cause a disc bulge or tear that pressurizes the nerve, causing muscle or sensory loss. If the disc injury is affecting both legs, you know the injury is severe because it was able to push directly through the PLL. This may cause complete loss of leg function, loss of bladder function, and/or loss of bowel function. This can require an emergency surgery.
Most disc injuries are treatable. We use traction (decompression) and therapeutic ultrasound for this. The primary goals are to reduce swelling, reduce muscle spasm, and increase mobility. Most people improve in symptoms when these goals are reached. Please contact us if you need help with your sciatica! Our phone number is 316-729-2528.
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