Many lovers enjoy the special closeness, emotional intimacy, and erotic intensity of intercourse with the man on top. But the according to a great deal of research, only 25 percent of women are consistently orgasmic in the missionary position no matter what size the man’s penis nor how vigorous or prolonged the intercourse.

Why? In the missionary position, the penis does not directly stimulate the clitoris, the trigger for  women’s orgasms. Sexuality experts have spent decades reassuring women and their lovers that women’s inability to reach orgasm with the man on top is (1) very common, (2) no reflection on the woman’s sexual responsiveness, (3) no reflection on the man’s sexual technique, and (4) no reflection on the relationship or how the woman feels about it.

These same sexuality authorities have encouraged couples in this situation to let go of the idea that women “should” have orgasms during intercourse. They have encouraged men to help bring women to orgasm by hand, or tongue, or sex toy.

In addition, they have encouraged couples to use two other positions that facilitate female orgasm during intercourse. In the woman-on-top position, with the woman straddling the man’s hips, he can place a fist at the junction of other lower abdomens, which allows the woman to press her clitoris directly against his knuckles and bring herself to orgasm. In the rear-entry (doggie) position, either lover can caress the clitoris by hand and provide enough stimulation for the woman to come.

But even when couples make these adjustments, many still wish the woman could reach orgasm during missionary-position intercourse. Enter the “coital alignment technique” (CAT). It was first introduced back in 1988, by sex researcher Edward Eichel, who claimed that it helped women have orgasms during missionary-position sex.

The CAT is deceptively simple: Instead of the man lying on top of the woman chest-to-chest with his penis moving in and out more or less horizontally, the man shifts himself forward so that his chest is closer to one of her shoulders. As a result, his penis moves more up and down. In other words, the man rides higher on the woman’s pelvis, and the bony base of his penis makes more contact with the woman’s clitoris. This increases direct clitoral stimulation and may provide enough to allow her to orgasm.

Eichel’s results with the CAT made headlines, and led to a flurry of magazine articles, and a book, The Perfect Fit. But for reasons that remain unclear, the CAT proved to be little more than a short-lived blip on America’s sexual radar. By the early 1990′s, the CAT was largely forgotten. For the past 20 years, few sex experts have encouraged couples to try it.

But quietly, research into the CAT has continued. A report in the Journal of Sex and Marital Therapy largely affirms what Eichel asserted: The CAT can help women reach orgasm during missionary-position intercourse.

In one study that’s typical of several, researchers worked with 36 women who could not reach orgasm in the missionary position. All of them, along with their partners, participated in an 8-week sexual enrichment workshop that taught sensuality and sexual communication and assertiveness skills. In addition, 17 of the women were encouraged to masturbate between lovemaking sessions to become more comfortable with their genitals and their sexual responsiveness, a standard approach in sex therapy. Meanwhile, the other 19 were taught CAT. Based on sexual diaries, kept during a 21-day period after this training, the masturbation group reported a 27 percent increase in orgasm during missionary-position intercourse, while the CAT group reported twice the increase, 56 percent.

Even if a woman can have orgasms during missionary-position intercourse, the CAT represents a positional variation that can feel intimate, enjoyable, and erotically novel. But for women who have difficulty reaching orgasm in man-on-top intercourse, the CAT may provide a technique for doing so. Happy experimentation.