Kneeling hogtie
From wipipedia.org
A kneeling hogtie is a variant of hogtie bondage where the victim is kept in a kneeling position. Support ropes may be used to ensure that the victim does not fall over.
As there is considerable pressure on the knees, the victim should be on a very soft surface and knee pads may be worn. If the victim is tied so that the feet are off the ground, this becomes a vertical hogtie.