The unflexed back and a low incidence of severe spinal headache.
D000758:Anesthesia; D000775:Anesthesia, Spinal / Q000150:complications*; D000776:Anesthesiology; D006261:Headache / Q000209:etiology*; D015994:Incidence; D051299:Post-Dural Puncture Headache
ANESTHESIA, SPINAL/complications; HEADACHE/etiology and pathogenesis