It seems that generally, there is a double standard between boys and girls for school physicals at least in the past, it may have changed in recent years as there are much less mandatory school physicals than in the past, not one by year, and I presume that they are performed for boys as for girls certainly with more respect of their privacy.
But in the past, a girl was generally more lucky than a boy if she was modest.
it was not seldom that the examination of boys was performed in group without any privacy in a large room as a gym or a hall, at least, they have to undress until underwear or brief or even completely naked in group in a locker room.
There was often one or several coaches or PE teachers present, of course, one or several female nurses of all ages, some young, others older, and the doctor was very often a woman too.
it could even happen that a shool adminitrative of both genders, male or female, was also attending at the exam or came occasionally in the exam room or the gym to just have a look and be sure that all was allright for the doctor.
nobody was really concerned by the modesty of the boys and they had not interest to complain because they were supposed to do exactly what they were told to do.
I doubt that girls were so bad treated?
Sometimes, they had to undress since the start of the exam for weigh in and height in public and it was very common that they had to be completely naked for one part of the exam, check of the spine (or if they were still in underwear, it was the time when the doctor pulled down it until their anckles before instructing them to remove it to walk a little naked to check the posture), also inspection of genitals, retractation of foreskin, check of the balls, check of hernia, sometimes visual inspection of the anus, cheeks wide apart.
At least, when it was not performed in public in a gym without any screen, it was in presence of a nurse.
During a long time, boys physicals in school were a little inspired by the militarian manners for physicals of draftees or inductees, so no privacy at all, no respect of modesty which is not a feeling that a boy under 18 age must have, no concern about who could see the boys and teenagers and rough manners during the exam.
So I have read several accounts of physicals and I am nearly convinced that those of boys are or were reallly much more embarrassing than those of girls and it was also my own experience in France when I was a student, but I recognize that may be there were or are some exceptions where girls were or are treated also very bad.