Double yonkyo

Uke’s forearm is controlled by a double yonkyo.

Before the rising phase (age), uke’s forearm is controlled by a yonkyo applied to the topside of the forearm.

After the descending phase (sage), uke’s forearm is controlled by a yonkyo applied to the underside of the forearm.

This can be seen in the video:

But be careful: these two symmetrical pressures on uke’s forearm are not applied either during the ascent or during the descent.

Otherwise, not only can the ascent and descent of yonkyo not be vertical, but they are even impeded to the point of being rendered impossible.