What is Sciatica?
Sciatica - when the sciatic nerve is compressed, irritated or inflamed - is a very common condition. Its symptoms include numbness, tingling, sharp pain, discomfort, muscle weakness, amongst others.
The sciatic nerve is a large nerve that runs down the back of the leg. At its thickest point it can be up to 2cm in diameter.
THE ANATOMY
The sciatic nerve is made up of nerve roots that exit the lumbar spine from L4 to S3. It then exits the back of the pelvis and continues down the back of the leg, branching off into various parts of the lower leg and foot.
The nerve roots exiting the spine from L4 to S3. These unite to from the sciatic nerve.
The sciatic nerve and it’s branches.
SYMPTOMS
As the sciatic nerve is made of both sensory nerves (they send information to the brain about what is happening in a particular area) and motor nerves (they stimulate the muscles to move) the symptoms can vary.
Common symptoms that can occur in the buttocks, thighs, lower legs and feet include:
tingling
pins and needles
burning sensation
crawling feeling
numbness
tightness
muscle weakness
aching
CAUSES OF SCIATICA
The most common cause of sciatica is a disc bulge or herniation in the lower part of the lumbar spine. The disc moves into the space where the nerve passes through and “pinches” or compresses it, causing symptoms down the path of the nerve.
However, there are other reasons someone might be experiencing sciatica. They include:
Piriformis syndrome: the piriformis muscle becomes very tight or spasms and compresses the nerve as it travels through the pelvis. In some people their sciatic nerve actually runs through the piriformis muscle which can make them more prone to sciatica. Hypertrophy, which is when a muscle becomes larger (think bodybuilders), can also put pressure on the nerve. This is common in runners who are overusing their piriformis instead of other muscles when running.
The sciatic nerve passes either very close or even through the piriformis muscle; it can be affected by tightness, spasm or hypertrophy of this muscle.
Stenosis: narrowing of the spaces where the nerves pass through. This can be as a result of discs become smaller or arthritic changes to the joints caused by wear and tear or inflammation.
Sacroiliac joint disfunction: as the sciatic nerve closely crosses the front of the sacroiliac joint it can be irritated by the irritation and swelling of the joint.
Spondylolithesis: where a vertebrae has slipped forward of its usual position. This will narrow the spaces the nerve has to pass through.
Retrolithesis: where a vertebrae has slipped backward of its usual position. This will narrow the spaces the nerve has to pass through.
HOW TO MODIFY YOUR PRACTICE WHEN YOU HAVE SCIATICA
If your sciatica is caused by a lumbar disc bulge or herniation, you will need to avoid flexion of the spine for a period of time. Postures where the lumbar spine is flexed include: standing and seated forward bends and many of the abdominal postures (especially ones where you are lying on your back). You may also need to avoid twisting and/or sidebending. The spine needs time to recover and strengthen and taking yourself into these positions can often slow down the healing process because it stretches fascia and muscles that are already overstretched. Gentle backbends will be helpful as well as postures where you are required to stabilise the spine in neutral.
Gentle backbends can help with lumbar disc herniations.
Strengthening the back can bring back stability to the injured area.
Chakravakasana is an example of a pose where you need to stabilise the lumbar spine.
If your sciatica is caused by your piriformis muscle it can be helpful to release that tension. Postures that stretch the back of the hip joint are ideal. Below are a few examples. It is important to note that if your sciatica is coming from your spine and not your piriformis muscle, all of these postures shown below will probably make it feel worse.
Jathara parivartanasana variation
Sukhasana forward
Gomukhasana - you can also fold forward to get a deeper stretch.
Lying face down in pidgeon is also a great way to stretch the piriformis muscle.
The other causes of sciatica are less common and require very specific adaptations to your practice. If you are not recovering from sciatica seek the guidance of an experienced professional - because with the right movements, as well as avoidance of aggravating activities, you can significantly reduce or eliminate the symptoms.
written by Jean Campbell
Interested in learning more about how anatomy relates to yoga practice?
Have a look at my Online Dynamic Yoga Anatomy Course.