You've seen it: A child with their legs splayed to either side of them merrily playing on the floor. But can this cute position — known as W-sitting — actually be bad for them?
This stability-enhancing position — the legs provide a stable base for the rest of the body — isn’t uncommon among children. As Dr. Ryan Curda, a San Diego-based chiropractor with Personalized Chiropractic, explains, “W-sitting is when a child sits with both legs significantly internally rotated and flattens their legs against the floor."
In other words, it's sitting with the legs arranged like a "W."
But is it a sign something could be wrong with your toddler? That’s a question that’s been discussed among parents and physicians... and the answer is nothing short of murky.
As children develop from newborn to baby to toddler, their bodies change substantially. They develop muscles, coordination and more. Some experts say W-sitting is just a part of development that works itself out as the child ages into an adult.
Dr. Donna Pacicca, an attending surgeon at Children’s Mercy Hospital in the division of Orthopaedic Surgery, section of Sports Medicine, and also associate professor of Orthopaedic Surgery at UMKC School of Medicine and adjunct professor of Oral and Craniofacial Sciences at UMKC School of Dentistry, is one of them. According to Pacicca, W-sitting is part of a normal condition known as anteversion.
"Everyone starts out in anteversion, and it gradually improves over time in most (probably due to in utero position, same thing that causes everyone to start out bowlegged),” explains Pacicca. "For the otherwise healthy and uninjured child, increased femoral anteversion means it's more comfortable to sit without stretching out the hip capsule (W-sit vs. criss-cross).”
For some, there’s more anteversion than for others, causing things like “toe-in” walking, Pacicca says. “This doesn't appear to cause problems later on, but there is controversy, especially for people with problems like recurrent patellar dislocation [a twisting in of the knee cap], about whether or not to correct rotational or angular malalignment,” she notes. “As far as in-toeing goes, again there is normal variation. It doesn't appear to cause issues with hips/knees as an adult per our current literature."
But can there be problems? Possibly... and it all has to do with the individual child and their development. In recent years, much has been written about the dangers of W-sitting to developing bodies.
Curda says the position limits the need for a toddler to develop trunk stability while they focus on other things. That stability is necessary for developing balance and coordination, which is why the position can be linked to developmental delays.
“Unfortunately, this leads to further trunk instability and delays the development of proper balance, cross body movements, and even playing across the midline on table-top activities,” says Curda.
That’s not all; a child’s developing hips can be impacted too. “Although I'm not aware of a long-term study showing the negative effects of W-sitting, I believe it would be reasonable to think that a decrease in trunk stability whether caused by W-sitting or other means would eventually lead to further health concerns," the chiropractor warns. That list of concerns includes everything from chronic or acute lower back pain to joint dysfunction of the hips and knees, improper muscle length and neurological firing of the back, pelvic and leg muscles.
According to Jean W. Solomon and Jane Clifford O'Brien, authors of the book "Pediatric Skills for Occupational Therapy Assistants," in children older than one year, W-sitting can lead to hip dislocation, joint deformities and more. Also, since it doesn't require trunk stability or strength, those muscles aren't used or exercised, so other sitting positions are preferable.
However, Pacicca says that not enough is known about the long-term impact of W-sitting.
“We still don't fully understand the molecular signaling that shapes the bones and joints; factors like joint arc of motion, skeletal alignment and joint laxity don't seem to be an issue now, but could potentially affect developmental signaling. We just don't know how or when that would happen at this time," Pacicca said.
So, what if your child W-sits? It depends, says Curda.
“If this sitting position is the norm and not the exception, it is advisable to coach your child to sit in a less stressful position. I'll leave it up to parents to decide the healthiest ways to accomplish such a change in behavior,” says Curda.
Some alternatives to consider encouraging your child try: side sitting, long sitting (sitting with legs stretched out in front) or tailor sitting (cross-legged).
However, if it’s not an always thing… then you might not need to worry after all.
“If your child sporadically W-sits, you should not be overly concerned as a parent,” says Curda.
Bottom line: If you're worried, tell your doctor. They can examine your child's body for signs of an issue.
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