Before revision: With the finger on the flexion point and palmar surface in a superior direction, note where the back of the finger makes contact with the fourchette (this is used to determine how far the ventouse cup must be inserted).
After revision: With the finger on the flexion point and palmar surface in a superior direction, note where the back of the finger makes contact with the fourchette (this is used to determine how far the ventouse cup must be