The main feature of spinal stenosis is painfully leaden legs that become increasingly heavy and unresponsive to walk. The effort to continue walking is crippling, as if you are painfully wading through treacle. There may be minimal or no pain when sitting or standing and moving about but the sheer painfully exhausted debility of walking - over increasingly short distances - literally brings you to a halt and stops you in your tracks.
The second and corresponding feature of vertebral stenosis is that you must sit down (or better still squat) to get relief, before you can resume walking. Sitting flexes (bends) the lumbar spine which broadens the small bony canals through which the nerve roots exit the spine (the intervertebral foraminae) and this lets more blood through. As the nerves receive a fresh flush of blood the pain and difficulty in the legs quite quickly subside. You feel fine, until you are stopped again moments later, further down the track.
The third important feature of true vertebral stenosis is that you go shorter and shorter distances before you are pulled up and must sit down again to gain relief. The last feature differentiates vertebral causes of the leg pain from vascular ones – in the condition known as ‘intermittent claudication of the legs’ when insufficient blood is getting through to the muscles of the legs.
One of the strangest features of spinal stenosis is the variability of symptoms from day to day. It is always more difficult walking uphill. But often, for no seemingly accountable reason, some days are better than others; the back 'feels lighter' and the walking easier.
The degree of swelling and vascular engorgement of the back's soft tissues is related to inflammation of the facet joints, which in turn depends on your recent physical activity (hard physical work chopping wood? or excessive sitting?). This, in turn influences the degree of muscle holding in the back. Excessive muscle protection is also related to mental states. You can read about this in more detail in spinal stenosis treatment.
While ever this variability exists, you would hold off on any type of back surgery.
The spinal cord is made up of long nerve fibres hanging down from the base of the brain like a descending plait of hair. The cord is housed by the spinal canal, the long bony tube inside created by the round holes of the vertebrae stacked on top of one another.
At each spinal level two spinal nerve roots pass out either side of the spine, squeezing past both the intervertebral disc and the facet joint. Both of these structures can swell when they degenerate and get in the way. As such, they are potential aggressors to the nerve root.
The disc is at the front of the spinal canal and the facet joint facet joints are at the back, in the diagonal back (postero-lateral) corners. The facet capsules are large to accommodate the enormous range of freedom (5-7mm) of the joint surfaces sliding on one another as you bend.
When facet capsules inflame, they swell and become 'space occupying' making a ring of canal obstruction at the problem spinal level. Where the canal is pinched into a trefoil shape it can cause both central and lateral stenosis. Disc bulging at the same spinal level can add to the constriction.
Facet joint enlargement makes the spinal canal more trefoil shaped (instead of round). This can obstruct clutter the spinal nerves
You can be born with a narrow canal, but it's usually cumulative degenerative changes that bring spinal stenosis symptoms to the fore. On top of that, there's often a salient back hurting incident that changes the way the back behaves, with a dawning realisation that walking is becoming difficult. In other words, the symptoms of vertebral stenosis invariably come on when you 'do something' to your back.
The variability of stenosis symptoms from day to day is caused by the stresses and strains of daily life, both physical and mental. This is why conservative treatment can be supremely effective - and you can largely do it yourself at home using a BackBlock. There are lots of gentle measures that can be done before opting for surgical treatment of spinal stenosis. In many instances, surgical treatment is embarked upon too hastily.
Variable soft tissue enlargement from facet joint arthropathy is the most likely explanation for stenosis
symptoms that vary from day to day
Spinal stenosis symptoms are caused by impeded vascular supply to the spinal nerves. We forget that nerves too need blood to relay messages to and from the brain. Fine blood vessels weave their way through the bundles of nerve fibres to keep each nerve healthy and firing electrical impulses to make the leg muscles contract.
Interruption of the blood supply to the nerves is caused by physical choking of the nerves, either in the central spinal canal, or the lateral recesses through which the nerve roots pass to exit the spine.
Why not simply sit back and watch? In this 14 video pack you will see Sarah take you through everything you need to know about your back and what to do with it
Many spines insidiously develop widespread degenerative disc disease DDD without your ever knowing. There can be a gradual bone growth throughout the internal cavities of your spine, rather like the build-up of scale inside a kettle. But just as the scale doesn't ruin your endless cups of tea, bony buildup rarely affects your quality of life. It is only when you develop additional soft-tissue problems on top that things becomes difficult – and require attention.
Calcification of the ligaments on the front of the facets joints (ligamentum flavum) makes vertebral stenosis symptoms harder to deal with conservatively
Variability of vertebral stenosis symptoms may also be caused by the multifidus muscle activity. These are deep spinal muscles that control facet joint opening and they can start behaving oddly when the joint is acutely inflamed.
On the other hand, with chronic spinal stenosis there may be thickening of the ligamentum flavum at the front of the facet joints that also impedes the blood supply to the nerves. I believe that passive hyper-extension of using the BackBlock and the spinal movements of the 'pressure change therapy' lumbar spine helps prevent calcification of the ligamentum flavum.
The deep spinal multifidus muscles control facet opening
Read more about Spinal Stenosis Treatment
Read more about Non-Surgical Options for Spinal Stenosis Treatment