why would a spinal tap using a needle to remove cerebrospina

why would a spinal tap (using a needle to remove cerebrospinal fluid) be done below the L2 vetebra ?

Solution

Collection of CSF from the subarachnoid space between L1 or L2 is more safe because the spinal cord will be present just above this and the nerve bundle called cauda equina present in this area is very slippery and can easily move away from the needle without any damage while taking the sample.