I think I recall a bone spur would keep you out. It wasn’t necessary to claim one. The army would doc would ask or would find it and tell you no. I had to go on a crash bulk-up diet for a month before the AF would let me in because I was underweight for my height. The Army didn’t give me the option. The army just said no.
My brother (who would have been Trump’s age now) had a draft deferment because of bone spurs. We were certainly not rich. It was the recruiting office that would not accept him.
I was in an Mech Infantry unit in Germany. We had a guy develop bone spurs. He wanted to stay in and even asked for a surgery to removed them. Nope, they put him out. Not enough Orthopedic surgeons available at that time.
when I went through processing before basic there were three of us that were under weight by about 2-3 pounds. we were instructed to go to lunch eat a much as we could and make sure not to go to the bathroom till after we were weighed.