Woman on top, also called the jackhammer, cowboy or cowgirl position, is a group of sex positions in which:

• the inserting partner lies on his or her back or sits in a chair, couch, etc.
• the receiving partner straddles the inserting partner and the partners face each other.
• the partners align the vagina
  Vagina
  The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
  
   or anus
  Anus
  The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
  
   of the receiving partner with the phallus
  Phallus
  A phallus is an erect penis, a penis-shaped object such as a dildo, or a mimetic image of an erect penis. Any object that symbolically resembles a penis may also be referred to as a phallus; however, such objects are more often referred to as being phallic...
  
   of the inserting partner to achieve penetration
  Sexual penetration
  Sexual penetration is a sexual activity that involves the entry into a bodily orifice, such as the vagina, anus or mouth, with a body part or an object....
  
  .

The cowgirl name derives from the image of the receiving partner "riding" the partner as a cowboy

Cowboy

A cowboy is an animal herder who tends cattle on ranches in North America, traditionally on horseback, and often performs a multitude of other ranch-related tasks. The historic American cowboy of the late 19th century arose from the vaquero traditions of northern Mexico and became a figure of...

 rides a bucking horse. It is one of a number of receptive-partner-superior sexual positions, another being the reverse cowgirl position. This position is also used as a precursor to the lateral coital position

Lateral coital position

The lateral coital position is a sex position described by Masters and Johnson in their Human Sexual Response. The position was preferred by 75% of their heterosexual respondents once they had tried it.-Initial advice:...

 described by Masters and Johnson

Masters and Johnson

The Masters and Johnson research team, composed of William H. Masters and Virginia E. Johnson, pioneered research into the nature of human sexual response and the diagnosis and treatment of sexual disorders and dysfunctions from 1957 until the 1990s....

.

This position is commonly cited as one of the more popular sex positions. It gives the receiving partner more control and also allows the inserting partner to view and caress the receiving partner's chest and abdominal region.

Variations

Reverse cowgirl

In another variation, the woman faces away from the man. She can either be in a kneeling

Kneeling

Kneeling is a human position in which the weight is distributed on the knees and feet on a surface close to horizontal.The position of kneeling may be assumed for practical reasons and for reasons of social or religious custom.- Practical reasons :...

 or squatting

Squatting position

Squatting is a posture where the weight of the body is on the feet but the knees are bent either fully or partially . In contrast, sitting, involves taking the weight of the body, at least in part, on the buttocks against the ground or a horizontal object such as a chair seat...

 position and can have her torso upright, or she can have it aligned with the inserting man's body. The woman has greater control over the extent and duration of the penetration.

This position can be used for vaginal or anal sex, with penetration achieved by a penis

Penis

The penis is a biological feature of male animals including both vertebrates and invertebrates...

 or a strap-on dildo

Strap-on dildo

A strap-on dildo is a dildo designed to be worn, usually with a harness, during sexual activity. Harnesses and dildos are made in a wide variety of styles, with variations in how the harness fits the wearer, how the dildo attaches to the harness, as well as various features intended to facilitate...

.

It serves to stimulate the most sensitive parts of the man's penis as a result of the way it is forced to bend while at the same time rubbing on the female G-spot and clitoris

Clitoris

The clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...

 simultaneously.

This position is widely depicted in male-female pornography

Pornography

Pornography or porn is the explicit portrayal of sexual subject matter for the purposes of sexual arousal and erotic satisfaction.Pornography may use any of a variety of media, ranging from books, magazines, postcards, photos, sculpture, drawing, painting, animation, sound recording, film, video,...

, because it enables the viewer to have a full frontal view of the woman, with the view of the man (except for his genitals) being of secondary consideration.

Disabilities

The reverse missionary position is one of a number of positions sometimes recommended for experimentation by partners in which the inserting partner has some form of disability. Dr. Ruth Westheimer

Ruth Westheimer

Ruth Westheimer is an American sex therapist, media personality, and author. Best known as Dr. Ruth, the New York Times described her as a "Sorbonne-trained psychologist who became a kind of cultural icon in the 1980s...

 wrote to the wife of a stroke

Stroke

A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

 victim that:

"Another area that you could explore would be a change of positions. The side by side position

Spoons sex position

The spoons position or spooning is a sexual position and a cuddling technique. The name derives from the way that two spoons may be positioned side by side, with bowls aligned....

 is sometimes helpful in these situations, as long as you make sure that the stroke victim is positioned so that the "healthy" side is uppermost. You could also try mutual masturbation, oral genital stimulation, the female superior position or the use of a vibrator."

See also

• Doggy style
  Doggy style
  Doggy style is a group of sex positions in which the receiving partner crouches on all fours with the legs slightly apart...
  
  
• Missionary position
  Missionary position
  The missionary position is a "man-on-top" sex position usually described as the act in which the woman lies on her back and the partners face each other. Though often acted on and applied by heterosexual pairings, it may also be used by gay and lesbian couples.The missionary position is an example...
  
  
• Sexual intercourse
  Sexual intercourse
  Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...