As with a herniated disc, spinal stenosis can cause back and leg pain, although the symptoms develop gradually, usually over several months or years.
Back symptoms: The patient experiences chronic back pain, usually at the waist, and especially when standing, walking or leaning backwards.
Leg symptoms: Patients may experience pain, numbness, or muscle weakness in the legs. The most common symptom is an ache or heaviness in the legs together with numbness, or a tingling feeling, like ants crawling on the legs. This happens after walking or standing for a long period of time, and will gradually disappear after sitting down or leaning forward. This is because the nerve compression is worse when the spine is extended backward. A patient with spinal stenosis cannot walk for a long period of time, such as when shopping, and they will have to sit down from time to time. In extreme cases, some patients cannot stand long enough to take a shower or brush their teeth.
Spinal stenosis is attributed to degenerative changes of the discs, ligaments and facet joints surrounding the lumbar canal. Wear and tear on parts of the spine can cause discs to bulge, ligaments to thicken, and joints to become enlarged because the body responds by trying to re-stabilize the back. All these changes cause the spinal canal to become narrower and the nerves to become more compressed, resulting in muscle weakness.