Sciatica

Wednesday, July 23, 2014

One of the most common reasons why our clients come to the Farnham Chiropractic Wellness Centre is because they are complaining of “sciatica”.

Sciatica is a commonly misdiagnosed and misunderstood issue. I have heard people complaining of “sciatica” when they have had lower back pain, buttock pain, back of the thigh pain (hamstring), side of the thigh pain, calf pain and the combination of all of the above. 

So what is sciatica? What can you do about it? How can you avoid it?

Let’s start with a definition:

“Sciatica” is actually a symptom, not a specific diagnosis. This symptom most commonly describes pain starting in the low back and radiating down the leg. It is either caused by damage to one or more of the low back / sacral nerve roots, or compression of the sciatic nerve as it runs down the back of the leg. 

Damage to the nerve roots most commonly relates to a disc bulge / herniation (known commonly as a “slipped disc”). I will write a separate blog about disc herniation as it is a large and important subject.

The pain is usually felt along the path of the effected nerve (dermatome) and is usually a “shooting pain” which travels beyond the knee to the foot. The sciatic nerve is a “mixed nerve”, meaning it has both sensory and motor functions. Hence, along with pain, you may also experience muscle weakness and / or numbness and “pins and needles”.

Anatomy of the Sciatic Nerve

The sciatic nerve is formed by the joining together of the nerve roots from L4-S3 (light blue in the picture) and is about the thickness of your thumb! These nerve roots join together inside your pelvis in front of the sacroiliac joint (SI joint). They run down toward the hip joint to exit the pelvis through a tunnel called the Sciatic Foramen.

The piriformis muscle crosses this tunnel (highlighted in blue on the right) and the sciatic nerve can either run under or through this muscle.

Due to the close relationship between the sciatic nerve and the piriformis muscle, sciatica can often be caused by spasm and inflammation in the piriformis muscle. 

The sciatic nerve then runs down the back of the leg between the hamstring muscles. Just above the knee, the sciatic nerve divides in half to form the tibial and peroneal nerves. The tibial nerve runs down the inside side of the calf while the peroneal nerve runs down the outside. They both curl around the ankle on their respective sides and end in the foot.

Common Sites of Sciatic Nerve Entrapment

Now that you understand more about the anatomy of the sciatic nerve, the next thing for you to understand is where the nerve can be “caught” or entrapped.

1) Disc herniation (AKA “Slipped disc”).

Your disc is an extremely strong and resilient structure. Almost always it will only get injured when it's has been weakened over many years of focal stress place upon it. This is due to poor movement patterns (compensation) or chronically poor posture. The exception to this rule is certain extreme acute trauma (car accident, sports injury).

When the disc bulges it can press on the nerve root either in the central canal of the spine or at the lateral (side) tunnels where the nerve exits the spine.

 

2) Soft tissue impingement.

The most common site of impingement from the "soft tissue" (muscles tendons and ligaments) is the piriformis muscle. As I have said above, the sciatic nerve either runs  under or through this muscle so when it is tight it can compress and irritate the sciatic nerve causing sciatica. So why does the piriformis get tight in the first place?

All muscles will go tight (spasm) when they are protecting themselves after damage. This is done to limit further damage. The reason the piriformis (and all structures in your body) gets damaged is due to focal stress, most commonly due to compensation.

The compensation usually occurs because your body is no longer working efficiently. This may be due to a structural problem, for example: an asymmetrical skeleton (like scoliosis, or leg length discrepancy); it may be from a mechanical issue like a damaged area elsewhere in the body (foot, hip, even shoulder).

Commonly, compensation is due to muscle weakness somewhere in the related "chain". For example, your glutes may be weak which would create an increase in workload on the piriformis. The most common reason for this is nerve interference caused by a stuck vertebra – called a ‘Vertebral Subluxation Complex’ (VSC). The most effective way to correct this problem is a well directed, specific chiropractic adjustment.

The piriformis itself may be weak due to a direct injury (trauma from a fall or collision), or there may be nerve interference affecting their motor control (VSC).

Other common impingement sights are the ligaments that make up the bottom of the sciatic foramen (sacrotuberous ligament), gluteus maximus, hamstrings, and calf muscles. The nerve can get caught up in scar tissue or spasm in these structures. The mechanism for the damage in the first place again comes from focal stress (explained above).

3) Lateral foraminal stenosis.

The nerve roots can be compressed anywhere in the spine but the relevant levels for sciatica are at L4-S3. The nerve roots exit the spine through bony tunnels called lateral foramina. These tunnels may be narrowed (stenosis) by a disc bulge or from excessive bone growth around the joints of the spine from long term wear and tear. Again this joint damage occurs due to focal stress from an unbalanced body which is usually avoidable / correctable in the early stages. The lesson here is, get checked regularly and fix the problem early.

When the cause of the stenosis is "bony", conservative (non-surgical care) can often help manage the symptoms but unfortunately surgery is often the eventual outcome.

Diagnosis

As I have said above, sciatica is just a symptom, so we need to find out where the damage is. I recommend that you contact a health care professional, like a chiropractor, osteopath, physiotherapist or GP.

The first thing that they will want to check is if the sciatica is due to nerve root compression from a disc. This will be done by performing clinical tests. An MRI scan maybe necessary in severe cases that don’t respond to care, but this will not usually be one of the initial investigations.

The clinician will palpate (fancy word for poke and feel) your lower back muscles, the muscles in your buttock, back of the thigh and calf. Areas of irritation that may be relevant to your problem will feel like tight bands or knots and often will recreate your symptoms. These are commonly known as “trigger points”.

Even when a disc is the problem, I find that there will often be multiple areas of irritation along the sciatic nerve’s path. These all have to be addressed for the best results.

Farnham Chiropractic Wellness Tests – Finding the Cause

Damaged areas listed above only tell part of the story. Damage only occurs when excessive force is focused on an area of the body, usually over an extended period. At the Farnham Chiropractic Wellness Centre we will do some extra analysis to find out the root cause of this focal stress. The combination of these test are not done in any other clinic that I know of.

One of our main diagnostic systems we use is ‘Proprioceptive Muscle Testing’. This is a hands-on process of challenging muscle reflexes. It gives us an accurate picture of how efficiently your body is working. We also use high tech equipment which measures the stress patterns around your spine and nervous system –‘The Insight Subluxation Station’.

By using these tests we get a unique objective view of which of your muscles are weak / inhibited and what the stress patterns are around your nervous system.

This is essential because if only the damaged areas are treated through manual therapy, medication or surgery, and the cause of the damage is not cleared out, the issue is likely to return.

Finding the underlying cause of your sciatica is essential to long term success.

Treatment and Management

Once you have had the cause of the sciatic nerve damage diagnosed, treatment will likely be necessary. The medical route is usually anti-inflammatories, pain killers and muscle relaxants. In years gone by, the general public would have been happy with this, but these days most people understand that while helpful in the short term, medication only masks the symptoms and doesn't fix anything. In some cases further damage can occur as the body’s normal feedback is removed.

Physiotherapy is a good option as they will give proactive advice, information and exercises. Hopefully some "hands-on" treatment will also be used to release the stress in the soft tissue.

Chiropractors and osteopaths are specialists in restoring joint mobility which will be important for sciatica patients. The relevant joints are those of the spine, hip, knee ankle and foot. I find that sometimes some even more removed areas will need to be freed up, like the neck or opposite shoulder.

As I have already mentioned, at the Farnham Chiropractic Wellness Centre we are specialists in Proprioceptive Muscle Testing. In my experience this the most efficient way of uncovering the underlying cause (of just about any injury). When the cause is treated, the effect often goes away.

Self Help

1) Ice and stretch – Reducing inflammation and gently stretching out the muscle spasm eases symptoms and promotes healing. Ice the painful area for about 15 minutes. This can be done every 2 hours and is best done in the first 48 hours after the initial acute pain. Click here for detailed instructions. Stretching straight after application of the ice can be very helpful. For sciatica the figure 4 and piriformis stretches are excellent. Video.

2) Keep mobile – I like to refer to this as “active rest”. This means that you are using your body but not straining it. Movement stimulates blood flow and breaks down adhesions (sticky bridges) in the joints, muscles and nerves.

3) Strengthen your core – After the acute pain has ease, a good strong core is essential for proper healing. The plank, side-plank, and bridge are excellent. You don’t have to hold ‘the plank’ for extended periods. It’s all about engaging the core, not about holding it. For example it is better to do 6 reps of 10 second planks than it is to do 1 rep of a 60 second plank. Video

4) Improve your posture – Posture is not only a static event. It’s the way we hold ourselves through movement and different static tasks. Maintaining a neutral spine is essential. The most common time we loose our neutral spine is when sitting and when bending. The hip hinge is the most critical habit to re-learn (yes, re-learn – you did it naturally as a toddler). The picture below shows how most of us bend. The picture on the right shows you how you should bend. If your hamstrings are tight add a slight knee bend.

5) Adopt an Anti-inflammatory diet – Avoid refined sugar (even be careful with fruit) and grains as they are inflammatory. A good quality Omega 3 is a natural anti-inflammatory with loads of other health benefits. The purest is Krill Oil.

6) Nerve Flossing – With all nerve entrapments, you have to get the nerve sliding to loosen the pressure on the nerve. Video

I hope that you have found this blog useful.

Understanding your body helps you be more involved in your own health care. I hope that you enjoy learning in this, and the future blogs.

Get well, stay well!

 

Grant Pretorius, M.Chiro, ART
Doctor of Chiropractic

P.S. Feel free to share this blog with any family and friends you may have that would benefit from this information.


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