Here's a short video from one of our basic classes last week on yokomen-uchi practice. This form of attack is often a weakness in many practices, as it is difficult to understand and challenging to both deliver and defend.
A few basic points when practicing yokomen-uchi:
1. Uke and tori distances (ma-ai) are slightly farther away so that uke can deliver the attack with proper form and power
2. Uke must be committed to the attack, putting their ki into the striking hand
3. Tori should enter slightly into the attack by a tsugi-ashi step, connecting at the elbow and lowering his/her center to disrupt uke's balance
4. When executing techinque, tori should not "block then grab" uke's arm. Rather, meet the strike at the elbow, settle your ki downward, then release uke's responding upward energy to allow their striking arm to return to the center of the action. Once it returns, tori can then re-engage it and complete the omote (or ura) waza. This is particularly complex, as you can see Endo Sensei demonstrate it here.
5. As a general kihon waza (testing) rule for yokomen-uchi waza, remember:
Lastly, please keep in mind that this particular practice focuses on yokomen-uchi from a kihon waza perspective. Of course, at higher levels of training timing and distance can be experimented with. An excellent example of this progression is explained by Tissier sensei here.
Questions? Comments? Leave them below.