An important factor in Japanese bondage is erotic stimulation by the ropes through the use of so called pressure points on the body that will reated a certain amount of erotic stimulation.
This is the schematic chart of where the pressure points can be found on the female body. You may have to search for them and the amount of stimulation is different from person to person. The prolonged stimulation of the points by the tension of the ropes crossing them is what creates the upbuilding erotic tension. By placing a knot directly on a pressure point, the effect is intensified.
The spianl pressure points are found just next to the spine, so not on top of it. Knots should therefore always be placed next to the spine. Since most of the knots will be made on the back, the stimulation of the spianl area usually is the most intense, causing the sub to want to wriggle her body to intensify the effect of the knots.
Alternate Use
Of course there is nothing against using these pressure points in an erotic massage. To do this, place your fingers lightly on one of the points and make tiny circles, leaving your fingers in one place at all times.
Except for the genital area the pressure points are exactly the same for men (so you can have your sub massage you in the same way). The “breast” pressure point excist on the male body as well but may sometimes be difficult to find.