First things first: Sports physicals and physical wellness exams are two different things.
Sports physicals don't require the comprehensive wellness check usually conducted at annual physical exams by pediatricians or doctors, which include everything from health history to lab tests to vision and hearing screening. They're not intended to.
Sports physicals are required by most schools and are intended to help prevent and protect teen athletes from sports-related injuries. These exams should find any problems that could interfere with physical activity, and usually that means concentrating on possible heart problems and previous injuries, so they can be prevented or properly treated before the season begins.