Sleeping positions

The sleeping position is the body configuration assumed by a person during or prior to sleeping.

It has been shown to have health implications, particularly for babies. Research by Chris Idzikowski, the director of the Sleep Assessment and Advisory Service, has suggested that the choice of position may indicate the type of person the sleeper is.

Health issues
In the 1958 edition of his best-selling book The Common Sense Book of Baby and Child Care, pediatrician Dr. Benjamin Spock warned against placing a baby on its back, writing, "if [an infant] vomits, he's more likely to choke on the vomitus." However, later studies have shown that placing a young baby in a prone position increases the risk of sudden infant death syndrome (SIDS). A 2005 study concluded that "systematic review of preventable risk factors for SIDS from 1970 would have led to earlier recognition of the risks of sleeping on the front and might have prevented over 10 000 infant deaths in the UK and at least 50 000 in Europe, the USA, and Australasia."

Pregnancy.org champions "SOS" (sleep on side), particularly the left side, for pregnant women, claiming this "will increase the amount of blood and nutrients that reach the placenta and your baby." A couple of research papers also link sleeping on your back during pregnancy with lower birth weight and increased risk of stillbirth, but these results must be corroborated by other larger studies.

It is recommended that people at risk of obstructive sleep apnea sleep on their side and with a 30° or higher elevation of the upper body. Snoring, which may be (but is not necessarily) an indicator of obstructive sleep apnea, may also be alleviated by sleeping on one's side.

Individuals
From his survey of 1000 people, Idzikowski identified six positions and claimed to detect personality traits based on them:
 * Fetus (41%) – curling up in a fetal position. This was the most common position, and is especially popular with women.
 * Log (15%) – lying on one's side with the arms down the side.
 * Yearner (13%) – sleeping on one's side with the arms in front.
 * Soldier (8%) – on one's back with the arms pinned to the sides.
 * Freefall (7%) – on one's front with the arms around the pillow and the head tilted to one side.
 * Starfish (5%) – on one's back with the arms around the pillow.

The remaining 11% stated their position varied or did not know. A Canadian survey found very different preferences, with 39% of respondents preferring the "log" position and 28% preferring to sleep on their side with their legs bent.

Couples
A Travelodge survey found that 50% of British couples prefer sleeping back-to-back, either not touching (27%) or touching (23%). Spooning was next, with the man on the outside 20% of the time vs. 8% with the woman on the outside. 10% favored the "lovers' knot" (facing each other with legs intertwined), though all but 2% separated before going to sleep. The "Hollywood pose" of the woman with her head and arm on the man's chest was chosen by 4%.

Directions
The Chinese feng shui and Indian Vastu Shastra systems describe favorable and unfavorable geographical directions (north, south, east, west) for sleeping. Feng shui also factors the configuration of the bedroom in the positioning of the bed.

Traditionally it is believed that the person who sleeps should place his head to east or south. Possibly, it is good to avoid west and north is never for good. Also there are beliefs which say, the person who places head to east learns quickly and the person who places head southwards remain virtuous. While west placing results in worrying and north to losses.