Sciatica specifically refers to symptoms arising from the sciatic nerve. It is an example of a “trapped nerve”.
The term is a commonly misused. Technically it only refers to pain in the distribution of the sciatic nerve, which typically presents as a clear line of pain down the back of the thigh (fig. B). If it passes the knee, it may cause symptoms into the calf, foot, or outside of the shin. Pain is typically sharp or shooting, and may present alongside numbness, weakness, or pins and needles.
There are similarities with:
- hamstring or calf injuries
- referred pain from the SIJ (the joint between the pelvis and spine)
- ischial bursitis
Your osteopath will take a thorough history and examine you to identify the cause of your symptoms.
Causes of Sciatica
Some causes of radiculopathy are illustrated above. The sciatic nerve is formed from a number of smaller nerves that exit from the lower spine (fig. A). Figure C shows how a bulging disc can compress the nerve within the spinal canal. Similarly, if the disc herniates and releases its contents into the spinal canal, the nerve can also be chemically irritated. Figure D shows a similar result from a spondylolisthesis- a movement of components in the spinal canal compress the nerve, again causing irritation.
Another cause of sciatica can be a deep gluteal muscle, piriformis, which leads specifically to piriformis syndrome. New or increased exercise can be a factor in developing piriformis syndrome. When addressed early, this is sometimes quicker to recover than other causes.
Some patients are told that sciatica is something they “have to live with” and that their only source of pain relief will be medication. Depending on the cause, this may not be the case. An Osteopath can work with you to diagnose the cause of your pain and look into treatment options.
The NHS recommends manual therapy (such as osteopathy) for sciatica. The guidelines highlight the importance of prescribed exercises alongside your treatment. Your osteopath will provide you with exercises tailored to you. As your symptoms improve, your exercises will be adjusted accordingly.
During your appointments, your osteopath may work on the local muscles and joints to improve mobility and ease the strain on the nerve. They may also work along the nerve itself to desensitise it.
Other nerves can be affected in this way, but as they are not the sciatic nerve, they do not cause sciatica. The femoral nerve runs down the front of the thigh, and behaves similarly when irritated. Treatment options would be similar if the mechanism was mechanical, such as pain caused by a muscle irritating the nerve, or a degenerating disc.