Sciatica is a term that’s often thrown about in the wrong context. Technically, sciatica is irritation of the sciatic nerve, which is a large nerve that runs down the back and side of the leg. It’s an example of radiculopathy- where a nerve is compressed or otherwise irritated, causing shooting pains, pins and needles, weakness, or numbness in the affected area. You can’t have sciatica in your arm, but you can have a radiculopathy of another nerve, and your osteopath may be able to help with both.
Anatomy of the Sciatic Nerve
The sciatic nerve is formed from a number of nerves as they leave the lower spine (fig A). They combine to form the sciatic nerve within the pelvis, then run down the back of the thigh. The nerve splits around the knee, with one portion running down the back of the calf and into the sole of the foot. The other branch wraps around the outside of the lower leg.
Potential Causes of Sciatica
Sciatica can be caused by a problem right at the start of its journey. Figures C and D show how spinal structures can impinge on the sciatic nerve. When discs bulge, they tend to push straight back, or backwards and off to one side. It’s the latter that is likely to catch a nerve, as this is where the nerves run. Fig D shows a (severe) spondylolisthesis, where a fracture or unusual anatomy cause the bulk of a vertebra to slip forwards, pulling on the nerve as it goes. Note that this is a rare condition, and unusual in that very few conditions actually cause something in the spine to be misplaced. Even when the bone is displaced, see that the disc remains firmly attached to both bones- even when a disc “slips” it remains connected to the bones above and below.
The nerve can also be irritated further down the body. One common example is piriformis syndrome. Through its course, the sciatic nerve runs close to (or sometimes even through) the piriformis muscle.
Therefore, if the piriformis muscle becomes tight or irritated, it can easily irritate the sciatic nerve, causing the symptoms of sciatica to spread down the nerve.
Managing Sciatica
Your osteopath is qualified to diagnose and treat your sciatica. Treatment depends on the cause of your pain, but will typically involve a combination of hands on treatment and exercises to continue at home.
When a bulging disc is involved, patients are often focused on “putting the disc back in”. The discs are very deep in the back, and they are under pressure from the rest of the body above, so they can’t be encouraged “back in” with much lasting effect. However, you may find that some exercises that make temporary room for the disc to recede do take the edge off your symptoms. The long term approach is to reduce the strain on the affected level by ensuring the rest of the back is moving well. We will also work to treat the rest of the course of the nerve.
Other causes may be best treated more focally. Soft tissue work, including massage and stretching for the piriformis muscle can have quick results, especially when combined with relevant lifestyle changes. Your osteopath will discuss these if they are relevant to your case.
