Here’s a great video showing Jodan Uke Ipponme, Nihonme, Sanbonme and Yonhonme.
Credit: Holger Lockertsen
This is from the Gasshuko in Oslo, Norway, june 2011.
Sensei Wim Massee (7. dan) gives valueable insight into correct technique when doing sanbon kumite jodan uke ipponme, nihonme, sanbonme and yonhonme.
Sensei Massee is in the World technical committee of Wado International Karate-Do Federation (WIKF)