Sciatica may begin either suddenly with physical activity or slowly. Sciatic pain has
aching and sharp components and radiates along a broad line from the middle or
lower buttock, proceeding dorsolaterally in the thigh in cases of compression of
the L5 nerve root and posteriorly in cases of compression of S1.
With L4 compression,
the pain is anterolateral in the thigh and may be misattributed to hip disease
If nerve-root pain extends below the knee, its location conforms to the superficial
sensory distribution of the affected spinal root.
Sciatica is usually unilateral, in
keeping with the common dorsolateral configuration of disk rupture and with
foraminal stenosis from osteoarthritic disease of the spine.