What is Sciatica?

Sciatica is a condition that Adelaide chiropractors see very commonly.

The term “Sciatica” is nerve pain arising from the sciatic nerve. It can be produced by pressure on the nerve roots as they exit the spinal cord, or by pressure on the nerve trunk of the nerve, where it passes through the buttock. Sciatica can be brought on by sitting on a hard seat. When your leg goes to sleep or develops pins and needles, that is similar to sciatica, except for the fact that it will usually resolve by itself within a few minutes. The concept is the same however, where pressure around a part of the nerve causes it to lose one or more aspects of its function.

The sciatic nerve is a large nerve, formed from nerve roots that originate from the spinal cord. These nerve roots pass out between the disc spaces and join up to form the sciatic nerve. It passes from the spine into the buttock, then into the back of the thigh and leg.

The sciatic nerve controls sensation and function to the leg and foot. In “true” sciatica, prolapsed or herniated discs tend to bulge and press directly on the nerve roots. Alternatively, herniated fragments of disc material in the spinal canal may trigger inflammatory reactions that cause localised swelling (similar to a sprained ankle swelling when injured). This additional fluid around the nerve roots may indirectly affect the circulation within the nerve roots and produce functional effects because of increased pressure. This pressure irritates the nerve, causing referred pain or other functional problems such as weakness or numbness.

The symptoms of sciatica can include:

  • hot pain in the buttock
  • aching in the buttock, back of the thigh (hamstring) and calf
  • pain in the ankle and foot
  • pins and needles
  • increased pain when lifting, straining or coughing
  • loss of power to the muscles of the leg and foot.

When the sciatic pain is due to a disk protrusion, it is not unusual for the pain to come on very suddenly, often with a seemingly minor movement. This is because discs have a very unusual nerve supply, which affects their ability to feel pain signals. If you were to slice through a disc horizontally (cross section), It would look like this

The nerve endings which have the ability to sense damage and produce pain signals only exist around the outer edges of the disc. This means that the disc can tear through two thirds of its width before any pain will be felt at all. This can happen gradually over time, but only once the outer edge is breached will it become painful, hence why people often report that the problem came on suddenly without any significant trauma.

Another tricky part of sciatica as a diagnosis is that other things can mimic the symptoms of sciatica. This is why chiropractors in Adelaide will perform a series of tests and assessments to determine whether your symptoms are those of true sciatica, or something else which presents similarly to sciatica. For example, mechanical irritation of the Sacro-Iliac Joints or the Lumbar spinal joints can also produce buttock pain and leg pain, pins and needles or weakness or inability to stand and walk. These situations will often respond to chiropractic care much more quickly than true sciatica.

Even when the tests indicate disc related damage, this can still respond well to chiropractic care. When correct mechanical function has been restored to the lumbar spine and pelvis, the normal healing processes that occur at a cellular level can proceed without being reaggravated by abnormal movements and actions. The normal healing time for a disc injury is around three months, however this doesn’t mean that you need to be in pain the entire time. Correct management of the injury with a systematic protocol of chiropractic care can often provide considerable relief while the tissue damage is healing.

Your Adelaide chiropractor is very well trained and qualified to help you assess your sciatica, determine the cause of it, as well as the best way to go about treating it successfully.