This involves the posterior and the abs and pelvic muscles are also engaged in this position.
The triceps, biceps and calves are also worked in this position and it is a highly advanced sex position which should be experimented with very carefully.
The position in which the partner stands is a quite challenging one as it requires one of the partners to lift the other one.
While thrusting partner uses a lot of strength, the receiving partner also thrusts back which involves the core and the pelvic region.
Description: In order to help oneself, the receiving partner can use a stash of pillows to support themselves but even then, muscles of the buttocks and inner-thigh would be worked thoroughly.