What is Sciatica? Osteopath Steve Morris Explains

Most people have heard of sciatica and many people have suffered from it but it still remains a misunderstood and often misdiagnosed problem, that’s shrouded in common beliefs which may not be totally correct. So I’d like to talk about sciatica and what the most common misconceptions are.

The most common thing that I hear is that “I’ve been told that I have sciatica.”  Sciatica is therefore presented as a diagnosis but surprisingly, Sciatica is actually a symptom. The diagnosis should recognise what is actually causing the nerve irritation. 

Sciatica is the term used to describe pain and other symptoms affected by irritation or entrapment of the sciatic nerve. Technically known as the S1 nerve root, it’s the longest nerve in your body, running from the base of your spine, right to the end of your big toe. It’s also the biggest nerve in your body and is about the size of your thumb at its widest as it runs through the pelvis.

More often nowadays sciatica is used as a generic term for pain in any part of the leg. But strictly speaking it should refer to pain going from the buttock, down the back of the leg and into the outside and under your foot. It may be associated with other symptoms like numbness and pins & needles in the same part as the pain or sometimes weakness in lifting the foot to the shin. 

Symptoms in any other part of the leg will not necessarily be coming from the sciatic nerve but from other spinal nerves as they come out of the spine at a different level. But the sciatic pattern is the most common.

Sciatica affects as many as 40% of people during their lives (1) and although the prognosis is good in most patients, up to 49% of patients continue to have symptoms for 6 months or longer (2).

However, Sciatica can very often be misdiagnosed, as an important aspect is that pain radiates into the lower part of the leg. I often see patients with buttock pain that have been told that they have sciatica but they don’t. They usually have a localised muscle spasm rather than a nerve entrapment.  So, any pain that does not extend past the knee is not likely to be a true Sciatica. 

So, you probably have sciatica if you have pain in the back of the leg, going past the knee and may have some pins & needles or numbness down the leg and under the foot or slight weakness in the foot, then you probably have sciatica. 

But a proper diagnosis should be made by a careful case history and proper examination by a healthcare practitioner who specialises in these conditions as sometimes there could be a very serious reason why you have sciatica. The nature of your symptoms and where they are will enable a good clinician to use a process called clinical reasoning, and get a pretty good idea what is most likely causing your sciatica and at which spinal level your problem is most likely to be at. 

This can then be verified by testing the individual nerve roots for any loss of sensation or muscle weakness and also identifying any changes in your knee or ankle reflexes. Nerve tests can also be done to assess whether there is any catching of the nerve as it runs through its nerve sheath, which would usually indicate a pinching or entrapment of the nerve.

I’m often asked by my patients whether they should be sent for an X-ray or an MRI scan. In general X- rays not very useful for diagnosing the cause of sciatica, unless this has come on after a trauma, as they only show any damage or changes to the spinal bones. 

SBPC ImageMRI scans are a little more useful as they clearly show the sciatic nerve and the intervertebral discs so bulging, prolapsed or herniated spinal discs, that are the most common cause of sciatica, can be identified.

But even though MRI scans are generally considered to be the gold standard for identifying the potential causes of sciatica, they are not always necessary, or even particularly helpful, especially if you have only had your symptoms for a few days or even weeks. We also need to be cautious with diagnosing these conditions purely from MRIs. 

Although MRI scans are able to clearly show up any disc bulge and the exact level that may be irritating the nerve, just like this image here (disc bulge circled in red), there can be a degree of ‘false positive’ findings. 

In other words, over 50% of the population may be walking about with some sort of disc bulge and have no idea that they have this (3). So, a diagnosis should always be made by ensuring that the clinical picture matches what is seen on the scan exactly and that it all ‘fits together and makes sense’. 

With that being said however, MRI scans can be very useful if your pain is getting progressively worse, even with treatment after 6 weeks and the clinical picture is not conclusive or if it’s not possible to identify the exact level of nerve entrapment from the examination alone. 

So now you know that you’re suffering from sciatica what should you do?

Initially the best advice is not to rest too much and to keep moving as long as it is not too painful. Gentle exercise which does not load your back, like swimming or cycling or very gentle walking can be tried and if OK should be done regularly. Heat on the buttock can help in most cases and mild anti-inflammatory can be used if the pain is too great or sleep is very disturbed. 

Generally, we would expect that your symptoms start improving within 3-4 days. But if this is not happening then it’s always best to seek professional advice as if caught quickly a more long term problem can be prevented. It is always a very good idea to find out what is causing the entrapment and this should be done by an experienced healthcare practitioner. 

At the Sussex Back Pain Clinic, we aim to relieve sciatica primarily by taking pressure off spinal discs and gently restoring movement in spinal segments where a nerve may be impinged or inflamed. Fortunately, in most cases sciatica can be relieved with a combination of manual therapy, simple exercises and restoration of proper function. 

But If the condition is severe or has not responded to manual therapy or exercise, we will most likely use IDD Therapy to ease the leg pain.  The goal is to treat the disc which may be pressing on the nerve and get mobility into the spinal segment by addressing stiffness in the soft tissues around the spinal segment and since 2010 we have helped many patients to get rid of their sciatica and get on with living their lives again.



1 Konstantinou K, Dunn KMSciatica: review of epidemiological studies and prevalence estimates. Spine (Phila Pa 1976). 2008;33(22):2464-2472.

2 Hasenbring M, Marienfeld G, Kuhlendahl D, Soyka D. Risk factors of chronicity in lumbar disc patients. A prospective investigation of biologic, psychologic, and social predictors of therapy outcome. Spine (Phila Pa 1976). 1994;19(24):2759-2765

3 Jensen MC, Brant-Zawadzki MN, Obuchowski N, Modic MT, Malkasian D, Ross JS. Magnetic resonance imaging of the lumbar spine in people without back pain. N Engl J Med. 1994;331(2):69-73.


Steve Morris is an Osteopath with over 30 years’ experience. He is a specialist in the field of non-surgical treatment of disc conditions, especially sciatica. He uses various different treatment mediums, from hands on osteopathy and acupuncture to the use of mechanical decompression with IDD Therapy, for which he is one of the country’s leading exponents and experts.

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