Not a TSDist, but the way I do it in Wado, the groin kick is an upward snap kick striking with the instep of the foot. Wheras a front kick wold require you to lift your knee more and strike in a more straight foreward motion inpacting with the ball of your foot.
It is one of the first kick we teach along with the front kick and the roundhouse.
This is the way we do it also. We sometimes call it a "punt kick" and anybody that plays soccer or football should be able to do this very well with great power.
Agreed that you will want to make sure you follow up with another strike as the attacker will most likely be bending over towards you.
And, agreed that you have a very limited opportunity to strike and you want to make sure you use the element of surprise to your benefit.
It is also effective to use this technique when attempting to defend yourself in other situations and you cannot get out of a grab or hold (choke hold, wrist grab, etc). It is also not the only technique possible, and on some people may not get the results you desire. In which case, give that attacker some more gifts!!! :hammer: