Good evening, to you also, my legs from knees down, went completely numb last evening, while sitting, took long time to have feeling to stand?

Numbness: If this was strictly a positional symptom, impingment of nerves which occurred at the groin from prolonged sitting could have been the cause. However if recurrent bouts of numbness occur, especially at other body regions, one would consider deficiencies of calcium, magnesium, potassium, vitamin b12, or neurological disorders like multiple sclerosis as possible causes. If needed see your MD,get tes