The need for a comprehensive understanding of normal growth and development, which enables the ems provider to better anticipate the physiologic and emotional needs of the child who is affected by illness or injury, is a principle of:

Family centered care.

Explanation:

Emergency medical services (EMS) is also known as paramedic services that treats illness and injury in emergency situation. The EMS provider provide medical services to the patients.

Family centered care is one of the important approach to understand the illness and injury of a child. The services in family centered care includes attitudes, values and services provided to the children with their families. Medical services including parent teaching is also provided in these centers.

Thus, the correct answer is family centered care.