Lumbar spinal stenosis

What it is

Spinal stenosis accounts for about 3% of mechanical low back pain. What matters most about it is that the spinal canal changes with the way the spine is held: flexion of the spine results in widening of the spinal canal and relieves the symptoms, while lumbar extension makes them worse.

How it presents

It presents as back pain, sometimes with sensory loss or weakness in the legs. Calf pain with ambulation that is relieved with rest or sitting is typical, and it is called pseudoclaudication. Two signs follow from this:

• Leaning forward relieves pressure and lessens the symptoms, which is the shopping cart sign.
• Symptoms are typically relieved while walking up-hill, because that results in flexion of the spine.