Final answer:
A radial pulse can generally be taken in children starting at 2 years of age, as the radial artery is more palpable at this stage, making the process easier and more reliable.
Step-by-step explanation:
The earliest age at which a radial pulse can be satisfactorily taken in children is usually around 2 years of age. Before this age, the radial artery can be too small, and taking a pulse can be difficult, thus healthcare providers often prefer other sites like the brachial artery. When assessing a pulse in children, it is crucial to consider the child's age and the most reliable pulse site for their size. While other arteries are readily accessible, the radial pulse is often used for ease and convenience once the child is old enough.