Small adhesive bandage. Lie on your side on the table. Draw your knees up toward your chin as far as possible. Bend your chin to your chest. Skin on back is cleansed with anantiseptic solution.
Local anesthetic is injected.
It causes temporary, stinging pain. Remain still, and breathe normally through the test. The spinal needle passes through the skin into the spinal canal to collect spinal fluid. Spinal fluid is removed. Pressure of the spinal fluid is measured before and after collection.