Just wanted to comment on the video showing suwari waza and hanmi handachi techniques, that I find the techniques brutal in my opinion. The techniques should be executed with control and LOOKING AFTER our partner not bashing him. Harmony should be found and in this video, I could not see this and the techniques seem rushed with little Zanchin in the end. That said, if these points were taken on board the teacher would execute very good techniques. (That is my opinion).
Coming back to the principles of Suwari Waza, I would say that the back is to be straight and the feet remain together and the movement forward should be done by bring one knee up and then the feet stay together for the backward movement the knees move together (without lift one knee up this time) and spread your knees sideways by keeping the back straight and keeping the same direction (keep your head facing forward whilst moving back or forward). Difficult to explain but easier to demonstrate here...
Hope this helps...
Follow us on Facebook at http://www.facebook.com/pages/Aspire...79305248800728
and Twitter https://twitter.com/AspireAikidoLon