Stand-up cyclist

Standing aids or standing trainers are devices designed for children who cannot stand on their own. They help children get to their feet. There are standing frames, which are static devices that lift children up and allow them to stand. They remain in the same place. Standing walkers are assistive devices that allow the device to be moved, i.e., to change location on wheels while the child is in a standing position. So you could also call them rolling standing frames? Both types of devices train standing, so they are also standing trainers.
They must be correctly measured by a medical supply store or therapist and adapted to the child’s height and physical limitations.