My son is a dreaded W-sitter. When I lovingly correct him, “Sit criss-cross-applesauce," he dinosaur growls and switches his legs around, or stands up and plays at a table - basically telling me that if he can't W-sit, then he won't sit at all! All I need is an eyeroll and I can officially hashtag it #threenager.
But what is W-sitting, and why should we correct it?
W-sitting is a common position for young children to play in, as they have much more hip internal rotation range of motion than us adults. If you walk into a preschool classroom, chances are you will see it; it's natural for children to move in and out of this position as they play. It is actually a very comfortable position for kids to play in, and may even feel more natural than tailor-sitting (criss-cross-applesauce) position.
In normally developing children, it isn't necessarily a big deal. It's good to encourage your child to sit in another position such as tailor-sitting or side-sitting because those positions allow for more trunk rotation, weight-shifting (so they can turn to grab toys not directly in front of them), and reaching across midline (across your body). These positions allow for better physiological development of balance reactions, core strength, bilateral coordination (important for using both sides of the body together), and crossing midline (important for writing). So as a physical therapist, I discourage my son from W-sitting.
Here is when and why you should be concerned:
- Excessive W-sitting may be a red flag your child's legs and/or trunk is weak. W-sitting is a very stable position, with a low center of gravity and wide base of support. Your trunk is locked-in as this position allows for very little trunk rotation, further increasing stability. So your child will not have to worry about keeping their balance while concentrating on playing with toys in front of them. If this is the case, you will likely see other signs of weakness, such as poor posture, delayed motor milestones, and excessive clumsiness/frequent falling.
If your child has been diagnosed with hip dysplasia (a congenital or developmental deformation or misalignment of the hip joint), W-sitting is important to avoid. It can significantly increase risk of hip dislocation in children with hip dysplasia due to the large amount of internal rotation stress through the hips. Furthermore, hip dysplasia can go undetected in young children and is often caught when growing adolescents start complaining of hip pain.
Other orthopedic concerns: Frequent W-sitting can also contribute to tight muscles which will further inhibit normal movement development, negatively affecting their balance and coordination. The major muscle groups placed in a shortened position during W-sitting include: hamstrings, hip adductors (inside of the thigh, important part of stabilizing the hip and knee when walking) and the achilles tendon (important for normal walking, running, and jumping). These tight muscles may result in walking pigeon-toed (feet turned in) and affect normal gait.
Avoidance of bilateral coordination: Since there is limited trunk rotation during W-sitting, children who do this tend to avoid reaching across their body, instead use their right hand on the right side and left hand on the left side. This can result in delayed hand dominance, important for hand dexterity, fine motor coordination, accuracy, and control. Bilateral coordination, also known as bilateral integration, is also important developmentally for coordination of gross motor activities such as running, skipping, jumping, riding a bike, catching a ball, and fine motor activities such as cutting paper with scissors, tying shoelaces, and using utensils. So frequent W-sitting can affect your gross and fine motor coordination development.
If there are already neurologic concerns or developmental delays: If a child has increased muscle tone or spasticity due to cerebral palsy or any other neurological condition, W-sitting will exacerbate abnormal patterns of movement, further restricting the child's ability to twist their hips outwards and move their legs apart. This results in increased difficulty sitting in side or tailor positions, which are postures that aid in the development of more desirable movement patterns and motor development.
In summary, W-sitting is a normal part of childhood development if your child is also playing in a variety of other positions (seated, tall kneel/up on knees, standing, etc) and easily moving in and out of these positions. If you find your child frequently W-sitting, or doing so for extended periods of time, correct them to “fix your legs!” or “feet in front!” and help them move into side-sitting, tailor-sitting, or long-sitting to help develop healthy habits and promote normal motor development.
If your child is unable to maintain a position other than W-sitting, then talk to your pediatrician, and ask about getting a referral for a physical therapy (PT) evaluation. Pediatric physical therapists can assess why your child is W-sitting, and help you come up with different positions and activities that your child can enjoy while playing in these alternate positions.