The vortex block is a combined defensive technique of Gedan barai and Jōdan uchi uke.
Manji uke is used almost exclusively in conjunction with Kōkutsu dachi. Areas of use are partner drills or bunkai applications, based on a free-fighting stance. In the kata, manji uke appears very often. For the first time the technique appears in Heian godan. It is most often used in the master kata Gankaku.
Here you will find all information about the techniques in the video