What is a crucial factor in the assessment of restraint use in young children?

The assessment of restraint use in young children primarily centers around weight due to its direct relationship with safety in restraint systems. When evaluating restraint use, it is essential to ensure that the equipment is appropriate for a child's size and weight to provide effective protection during transport. Restraints are designed to accommodate specific weight limits, ensuring that the harnesses or belts secure the child appropriately without risking injury in the event of sudden stops or accidents.

While age, height, and gender can provide additional context in understanding a child's development and safety needs, weight is the definitive measure that directly influences the choice of restraint system. Restraint devices often have defined weight thresholds that guide which system is suitable for each child, making it a critical factor in ensuring their safety during transport.