One of the possible apps is a leg grab takedown. Grab the leg (normally quite high up around the inside thigh but I guess it could be worked at different heights) with the hand that pulls back into "high uchi uke" and the "gedan barai" to the front punches and pushes to the groin. This does work as my instructor suprised me with it during some bunkai practice and I'm 6' 3" and think I was about 14 stone at the time (now pushing 16 stone - ouch) so I'm no lightweight.