Grab a comfortable chair or piece of furniture here; the giving partner is going to be carrying the weight of both people involved. Height is another thing to pay attention to when jumping into this position as the receiving partner's upper body weight is going to be resting on top of the table on which they're leaning their elbows. Experiment with taller - or shorter - tables if the receiving partner is resting too much weight onto the penetrating partner's lap.
Leaning the upper body onto the table, in combination with the use of the penetrating partner's legs and the back-end support provided by their partner, will provide the necessary lift for thrusting. This lift, when paired with the limited thrust from behind, will make for a decent level of penetration.
Because of the limited thrusting in combination with the muscle-tiring movement, the Knee Touch sex position can be a great fit for sex toys. A cock ring on the penetrating partner's penis or strap-on or a couple's vibrator can help drive both partners to completion. The receiving partner may also want to explore what sex toy options are available to them - especially with the extra room in front of their body. However, both partner's hands will likely be busy trying to facilitate the thrusting movement, so this may be a position that's better left to hands-free sex toy options like the Dame Eva 2, Hot Octopuss Jett, or electosex toys.