Can turtle neck syndrome be treated in children?

These days, I'm in a war with my child over the phone. We're in the middle of water play activities. When I look closely, it seems like only my child's shoulders are hunched and they have a turtle neck posture.ㅠㅠ

They are constantly nagging me to straighten my shoulders and chest every day.

Is it possible to treat my child's turtle neck with traditional Korean medicine? Will it be very painful? I am curious whether the child can endure the treatment and if treatment is possible.