W Sitting:

The myths, the facts and when to worry

By Nicole Pates, Paediatric Physiotherapist

Almost everyday in clinic W-sitting comes up. Through parental concerns, teacher advice, colleagues or social media. God forbid if you google W-sitting. The message is clear – W-sitting is bad for your child. Don’t let them do it at all costs! But is it? Is it really? What does the research say?

I wanted to be very clear on the facts, so I have looked high and low, long and hard, because I despise fear mongering, because I want parents to be empowered and informed, because I call on health professionals to do better. We have all seen whats happened in the adult based posture research and that its not how you sit but how long you sit but trying to get this message across after years of “ergonomics” is almost futile.

So what are the facts?
****Disclaimer: This information applies to typically developing children*****

1. W-sitting does not effect or change the shape of the hip bone. (1, 2, 4, 6, 13)
2. W-sitting does not cause developmental hip dysplasia (DDH) (3, 10)
3. W-sitting does not cause degenerative joint disease or arthritis (6, 9 11, 13)
4. W-sitting does not cause in-toeing (1, 12)
5. High quality prospective studies linking W sitting to gross motor delays, fine motor delays, core weakness or functional difficulties does not exist. (4, 10)
6. W-sitting is a preferred position for many preschool children (1)

Gorgeous E (21 months) giving us a fabulous example of what W sitting looks like.

Why do kids W-Sit?

W-sitting is a sign that your child has femoral anteversion. Let’s be honest. The normal value for adult hips is 15 degrees of anteversion. We all have anteverted hips… well the majority of us.

A. Normal Femoral anteversion at skeletal maturity B. Normal femoral anteversion in preschoolers 4-6 years C. Femoral anteversion and in-toeing

Femoral anteversion is NOT a structural abnormality or a deformity. It is a normal part of development. There is a wide range of normal.

W-sitting does not cause femoral anteversion, however femoral anteversion means W-sitting is comfortable – that’s why so many kids choose it! It also means sitting cross-legged, or for our American friends “crisscross applesauce”, is not comfortable and hard.

As children grow, their hips “unwind” and the amount of femoral anteversion reduces and you will see them “grow out” of W-sitting by 8-10 years old.

W-sitting is usually seen most commonly in preschoolers and early school, however some people never outgrow it – and usually their parents/grandparents/aunts/uncles can still sit like this. It is also a common sitting position for young and old in Asian cultures.

If you have ever practiced yoga, it might be a position you are working towards Virasana (or hero pose). This pose has many purported benefits — from stretching the hips, thighs and feet; improving circulation and relieving fatigue in the legs; and strengthening the arches of the feet and correcting posture (hang on what? Isn’t this opposite to what most children get told?!)

However, at least now you understand why you might be struggling to achieve this pose without props, your femoral anteversion or hip inward rotation just doesn’t cut the mustard.

So why do health professionals make a fuss about W-sitting?

To be honest, it’s very rare that typically developing children who just W-sit come in to clinic. Usually parents bring their children when there are other things happening and W-sitting is just one small part.

But if that is all we see; children who W-sit and have trouble walking, moving in and out of sitting, or other diagnosis, sometimes we start to attribute W-sitting as part of the problem… when actually, for a small group of typical kids (~5%), it is just a sign of an underlying problem.

For 95% of kids, there is no cause for concern. W-sitting is comfortable during early childhood and they will more than likely “outgrow” this position by 8-10 years old. Altinel et al 2007 found that of 1134 children aged 3-6 years, 64% preferred to sit in the W-sit position. However, only 6% had in-toeing gait (3/4 of these being both legs in-toe) – so not all children who W-sit in-toe.

For the other 5% there might be something else going on, and it’s up to us, as paediatric physiotherapists and occupational therapists to screen for children who fall into special populations (see below) or to figure out and address the underlying cause.

For example, significant femoral anteversion — that is, more than 2 standard deviations above the mean for their age — can be associated with, not cause, more frequent falling and more tiredness with walking long distances (Leblebici et al 2019).

A paediatric physio will be able to assess, monitor and demonstrate your child’s femoral anteversion and inward hip rotation.

Food for Thought

Some children, may sit in a W to reduce the physical demands of sitting, to allow them to increase their focus, attention and concentration on the task in front of them. Does shifting them into a position that “works their core” actually detract from their ability to do the task? Can they get “core strength” from other activities such as climbing, riding and monkey bars? A small, adult study actually showed that there were no differences in trunk muscle activity between sitting positions.(7)

When should I seek help from a health professional?
There is always the other 5%, and our job as paediatric physios is to make sure we don’t miss these 5%! The earlier we can intervene, the better.

You should seek a review for your child if, in addition to w-sitting you see:

• pain or tiredness
• frequent trips or falls
• gross motor delay
• in-toeing, especially if its only on one side
• low muscle tone (ie. if they were delayed in their gross motor skills in infancy)
• high muscle tone
• W-sitting is the only position they use and they cannot get in and out of this position easily

However, as a parent, you are the expert in your child. If you are not comfortable with your child using this position there are many other play positions that we can suggest.

E adopting a side sit position, 30 seconds after the initial W sit position photo was taken. E demonstrates beautiful ability to move in and out of different sitting postures, has no in-toeing gait and above average gross motor skills.

Special Populations

For children with a diagnosis that causes high muscle tone (i.e. Cerebral Palsy, Spina Bifida), or low muscle tone (Down Syndrome), or a genetic condition that results in connective tissue laxity (Down Syndrome, Ehlers Danlos Syndrome)

Compensatory postures: Slouched sitting and W-Sitting (Breath 1997)
These children may rely upon these wide based compensatory postures pictures above, limiting their ability to develop and use their postural muscles. The muscles of these children have neurological differences (i.e. spasticity) and this may affect bones if there are spending long periods in these postures. Either position as seen above can limit a child’s ability to reach, rotate and move in and out of position. This then becomes an issue if a child is spending a long time in these positions and their muscles are of a different tone.

These positions do however create a nice stable, wide base and allow the children to be “hands free” sitters and engage in play. Physiotherapists and occupational therapists can help these children by providing positions, supports and seating to enable hands free play in more ideal sitting postures.

A Note for Teachers
Remember;

• W-sitting is a preferred sitting position, especially for pre-kindy, kindy and pre-primary kiddos
• It is not going to “harm” the child’s bone development
• Kids who prefer to W-sit might not be comfortable in the cross legged position
• If you notice a kiddo just prefers to sit in the W-position most of the day, has trouble keeping up with classmates in the playground and/or struggles with tasks  in class – these are the kids that need onward referral.

Food for thought: More and more we are seeing in the literature, especially in adults, it’s not HOW you sit but HOW LONG you sit that leads to problems. There is also more evidence to suggest that children are becoming more sedentary earlier in life… but that’s a blog for another day!

References

1. Altinel, L., Köse, K. C., Aksoy, Y., Işik, C., Erğan, V., & Ozdemir, A. (2007). Hip rotation degrees, intoeing problem, and sitting habits in nursery school children: An analysis of 1,134 cases. Acta Orthopaedica Et Traumatologica Turcica, 41(3), 190.
2. Frye, S. (2017). 7 lower limb positional variations (pp. 16-24). Contemporary Paediatrics.
3. Goldstein, R., Nazareth, A., Ziarati, P., Mueske, N., Rethlefsen, S., & Kay, R. (2019). Hip Dysplasia is Not More Common in W-Sitters. Pediatrics, 144(2), 770.
4. Honig, Evan L.a; Haeberle, Heather S.b; Kehoe, Clare M.b; Dodwell, Emily R.b. Pediatric orthopedic mythbusters: the truth about flexible flatfeet, tibial and femoral torsion, W-sitting, and idiopathic toe-walking. Current Opinion in Pediatrics 33(1):p 105-113, February 2021. | DOI: 10.1097/MOP.0000000000000977
5. Leblebici, G., Akalan, E., Apti, A., Kuchimov, S., Kurt, A., & Onerge, K. et al. (2019). Increased femoral anteversion-related biomechanical abnormalities: lower extremity function, falling frequencies, and fatigue. Gait & Posture, 70, 336-340. doi: 10.1016/j.gaitpost.2019.03.027
6. Lincoln, T., & Suen, P. (2003). Common Rotational Variations in Children. Journal Of The American Academy Of Orthopaedic Surgeons, 11(5), 312-320. doi: 10.5435/00124635-200309000-00004
7. Lee D, Yu S, Song S, Lee SH, An S, Cho HY, Cho KH, Lee G. Comparison of trunk electromyographic muscle activity depends on sitting postures. Work. 2017;56(3):491-495. doi: 10.3233/WOR-172515. PMID: 28269810.
8. Rachel Y. Goldstein, Alexander Nazareth, Parisa Ziarati, Nicole Mueske, Susan Rethlefsen, Robert Kay; Hip Dysplasia is Not More Common in W-Sitters. Pediatrics August 2019; 144 (2_MeetingAbstract): 770. 10.1542/peds.144.2MA8.770
9. Rerucha, C., Dickison, C., & Baird, D. (2017). Lower Extremity Abnormalities in Children (pp. 226-233). American Family Physician.
10. Rethlefsen SA, Mueske NM, Nazareth A, et al. Hip dysplasia is not more common in W-Sitters. Clin Pediatr (Phila). 2020.
11. Ryan, D. (2001). Intoeing. Orthopaedic Nursing, 20(2), 13-18. doi: 10.1097/00006416-200103000-00006
12. Sielatycki, J., Hennrikus, W., Swenson, R., Fanelli, M., Reighard, C., & Hamp, J. (2016). In-Toeing Is Often a Primary Care Orthopedic Condition. The Journal Of Pediatrics, 177, 297-301. doi: 10.1016/j.jpeds.2016.06.022
13. Staheli, L. (2001). Practice of pediatric orthopedics. Philadelphia, Pa.: Lippincott Williams & Wilkins.