Leapfrog is a sex position in which a woman is on all fours with her head and torso lower than her hips. The man penetrates her vagina from behind in a kneeling position. This, as with most positions in which the man enters the woman from behind, allows the male partner to ensure that the woman reaches a satisfactory orgasm by manually stimulating her clitoris. This position also allowes the male partner to control his thrust speed more easily, providing the desired speed and stimulation for the female partner. Penetration can be very deep.
The woman also has the option of rotating her hips against his penis as she is penetrated giving added sensation to both partners.
One disadvantage of this position is it can cause strain on the female's back.
This position is also known as "face down ass up".