Once you have established CSF flow, attach the stopcock and manometer to the lumbar puncture needle. The arm of the stopcock should be in the down position. It is very helpful at this point to have an assistant hold the top portion of the manometer for you. When attached, ensure that the connecting tube between the stopcock and the manometer is at the same level of the LP needle. This avoids falsely elevating or lowering the pressure reading. At this point, ask your patient to relax their legs and slowly straighten them.