Why does medical puncture lumbar puncture needle ache after operation?

Lumbar puncture is to enter the subarachnoid space by puncturing the skin, subcutaneous tissue, supracospinous ligament, interspinous ligament, ligamentum ligamentum, epidural and enter the subarachnoid space in order to obtain cerebrospinal fluid. When the needle passes through the above tissues, there will be certain damage, but these injuries are sterile and small, but it is also an injury that cannot be ignored. Even a small nerve may be damaged, so the phenomenon of lumbar distension after puncture is relatively common.