Why don't we fall out of bed while we sleep?
ASK A RESEARCHER: And why does it happen to kids?
Published
Most of us sleep in beds that are around 60-70 centimetres high, and falling out in the middle of the night could result in significant injuries.
This almost never happens to normal, healthy adults. However, anyone with experience caring for young children knows they can easily fall out of bed.
"There are two groups that typically struggle with falling out of bed: Children and the elderly," Ståle Pallesen tells sciencenorway.no.
He is a researcher and specialist in sleep disorders at the University of Bergen.
When we sleep, both in deep sleep and during REM sleep, our bodies have a mechanism that partially shuts down and limits our muscles. This prevents us from acting out the things we experience in our dreams.
Parkinson's and sleep
In older individuals with conditions like Parkinson's or other dementia-related diagnoses, this mechanism can stop functioning properly.
"This mechanism can fail in people with such diagnoses," says Pallesen.
Elderly people with such sleep disorders can harm both themselves and their partners by moving during the night.
Children also move much more than adults when they sleep, which increases their likelihood of falling out of bed.
“Children haven’t yet developed a full integration of their sensory perceptions,” he says.
This affects their ability to orient themselves.
"This ability is weaker in children than in adults. It's harder for them to understand where the edge of the bed is," he says.
This suggests that even during sleep, we maintain a certain level of awareness, according to Pallesen.
"There's always some level of sensory processing happening, even during sleep," he says.
Bunk beds and drunk adults
This is also why children's beds need extra safety measures to prevent falls and injuries. Pallesen references a 2008 study from the USA showing that many children sustain injuries in bunk beds from falling, jumping, or due to bed defects.
"It's very important to follow recommendations and secure beds with proper barriers and bed rails to prevent falls," says Pallesen.
Adults generally remain more still, but alcohol can disrupt the body's ability to keep muscles at rest.
"This increases the likelihood of falling out of bed," he says.
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Translated by Alette Bjordal Gjellesvik
Read the Norwegian version of this article on forskning.no
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