What is in a vaginal examination, the act of imparting through the uterine wall with the finger a shock to the fetus, so that it bounds upward, and falls back again against the examining finger called?

repercussion — (Obstetrics) In a vaginal examination, the act of imparting through the uterine wall with the finger a shock to the fetus, so that it bounds upward, and falls back again against the examining finger. (Webster's 1913.)