It's not uncommon to see children sitting in the 'W' position, especially when settling down in front of the TV.
But experts are warning that this could cause them a lifetime of pain, impacting how they run and jump.
The 'W' position involves the child sitting on their bottom with the knees bent and feet pointing outwards, Mirror reports .
According to the Pediatric Therapy Center , children who sit this way after their second birthday may not develop the core strength and balance.
And this could impact their ability to jump and run.
It could also impact muscles in their legs, hips and ankles and could even cause hip dislocation, reports Women's Health.
London-based osteopath Avni Trivedi has also raised concerns about the position, saying it could cause children a lot of problems in the long run.
She said: "Sitting for too long generally can place undue pressure on the neck, shoulders and upper back.
"For children that may be hypermobile, sitting in the 'W' position may overstretch the joints and can weaken the trunk muscles as they are not required to be active."
Instead, parents should encourage their children to sit crossed-legged instead, or sitting with their legs to the side or out in front of them.
