Where in the vertebral column is a lumbra puncture generally done?

Answer 1

A lumbar puncture is usually done between the third and fourth lumbar vertebrae (L3 and L4) as, in adults, the thick part of the spinal cord has ended by this point, meaning it can't be damaged by the lumbar puncture. The nerve fibres in this area are called the cauda equina (horse's tail) and they actually seem to move out of the way as the needle passes though into the cerebrospinal fluid.