Spinal Canal Stenosis
Lumber Spinal Canal stenosis is a narrowing of the spinal canal, which may cause nerve impingement, and it can occur in the central canal, the lateral canal or at the foramen. It is a common cause of Low Back Pain. Normal lumber spinal canal is more than 150 mm2. Degeneration of the spinal canal and thickened ligamentum flavum will couse Spinal Canal Stenosis. Absolute Stenosis=spinal canal less than 100mm2.
Central Canal Stenosis:-Degenerative changes involving thecal sac, facet joint and ligamentum flavum will cause Central Canal Stenosis.
Lateral Canal Stenosis:-Narrowing and compression between the sac and medial pedicle wall, it effect the transversing nerve root. Superior facet, facet capsule, disc hypertrophy and degeneration are the causes for Lateral Canal Stenosis.
Foraminal Stenosis:-Lateral to the medial pedicle effect the exits of the nerve root, facet enlargement, overriding or disc degeneration causes for Foraminal Canal Stenosis.
Pain will increase in backward bending because spinal cord goes down, foraminal area decreases by 20% during extension & foraminal area increases by 12% during forward bending. So forward bending is comfortable rather than backward bending for the Spinal Canal Stenosis Patients.