Some children has difficulties with gravitational insecurities. They might not know where their body is on space and they feel like they're falling. Sometimes when they're on a curve, they may feel they're on 10ft high in the air,
These children tend to move slowly and carefully and may refuse to participate in activities.
You have to help your child out with physical prompting to be able to adjust themselves and realize that it's not that far down.
Sometimes, when children lie down on a bed, or sit down on a couch, they feel like they're falling. They feel vulnerable whenever their feet leave the ground. This may be why your child often avoids or is fearful of trying new activities on the playground, at home, or at school.
So giving them some pressure into their body and into their joints and actually giving them the opportunities to try those situations out in their daily lives will help them.