"The plantar fascia is in a relaxed position when you're sleeping, " says Jacqueline Sutera, a podiatric surgeon in New York City.

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This experiment does, however, suggest that genetics alone may explain some cases of SIDS. In the past, explanations have concentrated on environmental factors such as the smoking habits of the parents, bacterial infection and (most famously) a baby's sleeping position.

ECONOMIST: Sudden infant death syndrome

When people want stress relief, they tend to go for massage-the manipulation of muscles, the prone sleeping position and the feel of another's hands all create a comforting environment.

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The new ones (bottles) came at a time when his position was that he was sleeping in the living room next to his mother, or something like that.

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