膝車 & 支釣込足 / Hiza-guruma & Sasae-tsurukomi-ashi 

I think its wheeling/ rotating nature of guruma throw vs. sharply and forcefully stopping advance of the ukes foot in sasae.

@@DonSamRazYo I think Sasae means stopping, Guruma is wheeling.

Well, that is the exact distinction described by the late Daigo-sensei. Other details, e.g. to stop the advancing foot to perform Sasae-tsuri-goshi („Uke stumbles over“) or attacking the far leg of Uke in Hiza-guruma, seem to outline the application in Randori/Shiai. In the technical japanese description even the same word for the action of toris foot is used for BOTH throws: sasaeru (supporting/holding; which in his meaning is more than simple „blocking“). It is indeed often unclear where the Kodokan switches or distinguish from basic principle to application or vice versa. PS/sidenote: they mentioned „lifting“ (??) Uke forward within Kake of Sasae in the Video, Daigo-sensei doesn‘t mention that anywhere. Maybe again a problem with translation or language Interpretation.