At my time in the beginning of 60's in France, there could be a lot of mandatory physical examinations, so I am a little surprised when I read that some of you have had only one in elementary school for instance..
Like I have already said, it was one year of school from beginning in elementary school since graduation at high school and even later at university or superior school.
At university it was one by year like at middle or high school and mandatory also if you wanted to go to the next year and be allowed to follow your studies. You had not to strip completely before entering in the examination room, and depending on towns, you were instructed to undress in briefs or to stay dressed to wait and you were generally examined alone in front of doctor and female nurse. But I have heard rumors about a university in a town where the set up was different, the male students were summoned all together in a large group in a big room and instructed to line up naked to be examined by a few doctors one by one but in plain view of the others and with female nurses to perform some exams and all the male students were always stark naked for all the duration of the exam. Officially this set up was decided by doctors to win time and be efficient because of the great number of students to be examined. After a few years, there was some complaints of students to university authorities and there was a change of doctors and of the set up for examination.
At superior school after graduation from high school, there was always an entrance physical examination which was rather thorough and embarrassing because the doctor -male or female- was generally assisted by a nurse to take notes or perform some exams and help the doctor, so it could be embarrassing even if you were examined alone and if you were not instructed to strip completely in the waiting room.
Besides school examinations, there was normally a lot of other situations where you had mandatory physical examinations mainly performed in group at least for undressing. For instance if you went to a summer camp, there was always a physical examination a few days or weeks before the departure, it was mandatory and annual, and you were summoned to report in a medical facility by group of about 10. Until you reached the age of 12 or 14, you might be accompanied by your mother and you were instructed by a female nurse to undress in briefs ( white and tight at that time) all together in front of all the mothers and to sit on benches to wait until you were called by her, then you entrered in the examination room with your mother who could watch all the examination which included always inspection of the genitals, palpation of testicles, retraction of the foreskin, cough and turn test for hernia, and chek of balance and spine with butt exposed naked. All the exam was performed by a doctor mainly a woman in front of the nurse and the mother. There could be also present a female secretary to watch all the examination to check identity and to fill the medical form.
After 12 age, or sometimes 14 age, normally you could come alone without your mother but the set up was the same with undressing in briefs in group.
A friend of mine told me that at 16 age he was naked in front of a female doctor and a female nurse and a female secretary sitting behind a desk on the side of the room and they made him walk naked forth and back in the room to check his spine and balance under the eyes of the female secretary. It might be one of her most funny days each year.
I have not been submitted to these physical examinations myself because I never went on summer camps, I spent my holidays with my parents, but I have heard several times relations by some friends classmates who had to go to these annual physical examinations.
Of course even if I presume that there was some official forms with mentions about how such examinations might be performed, I think that they let the doctors or summer camp authorities or community authorities when they were carried on in a community center decide how to proceed and how undressed the boys might be and how thorough the exams might be, because the official forms might not be too much detailed about the process of the physical examination for summer camps.
It was the same if you wanted to do sports outside the school in a club or be member of a sport team, you had each time to report at a physical examination before being allowed to do sport and be member of a team. Generally, according to relations of friends, the physicals examinations were performed in group when they were rather fast or alone in the examination room or behind a partition but always with undressing in group before when they were more thorough. The exams were performed by a doctor assisted or not by a nurse and possibly also in presence of a female secretary and more often in presence of one male coach ( or possibly two). A medical form filled by family doctor was not valuable. Boys might be examined by the doctor assigned to perform their physical examinations.
I did not like sport but I had to subscribe at a sport association to learn to swim at 15 age because I had not learnt it at midlle school, it was free of charge if you were the son of an employee of the society to which belonged the association but you had to report in the nurse office of the society facilities for a physical examination with other boys at the same time.
Each boy might be accompanied by his father or his mother. We were a group of ten boys between age 14 and 16 since we would be in the same group after for swimming lessons. At our arrival a female nurse instructed us when she thought that we might be all present to undress in just briefs ( bare chest, bare feet, no watches, no jewelleries) and then once undressed she did a roll call ( she could have done it while we were still dressed but she obviously prefered to do it while we were already undressed in briefs) and after we were called one by one and instructed to strip naked inside the examination room in front of a doctor, the nurse, and for me my father. I am sure that it was the most common way to proceed in such mandatory physical examinations, we could even be lucky according to relations of some friends in other situations to have been told to strip in briefs and not naked as it could be even in front of fathers or mothers.