Like males, common positions for female masturbation include lying on back or face down, sitting, squatting , kneeling , or standing. Sexual climax, from masturbation or otherwise, leaves one in a relaxed and contented state. Some may lay in the prone position and rub their genitals against the bed sheet or other surface, a technique called prone masturbation. Some women can orgasm spontaneously by force of will alone, although this may not strictly qualify as masturbation as no physical stimulus is involved. Mutual masturbation foreplay The manual stimulation of each other's genitals where the session eventually leads to sexual intercourse. It could be caused by a low-grade urinary tract or yeast infection, or the child may be overstimulated and in need of soothing, or indeed understimulated and bored. Some EU Nations promote masturbation in their sex education curricula. The symptoms last for up to a week. The strength of these correlations increased with increasing frequency of ejaculation. The Latin verb masturbari is of uncertain origin. A good quality personal lubricant is advisable to both increase the pleasurable sensation and aid insertion. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. The mechanism is through stimulation of the sympathetic nervous system and is long lasting. Intercourse, by itself, is often inconvenient or impractical at times to provide sufficient sexual release for many people. A small study demonstrated lower blood pressure in persons who had recently masturbated compared to those with no proximate sexual activity. The most common masturbation technique among males is to hold the penis with a loose fist and then to move the hand up and down the shaft. Lying face down on a comfortable surface such as a mattress or pillow, the penis can be rubbed against it.