There are many theories about this. I remember there are two legendary. One is that the population of Hongdong in Shanxi moved to Shandong in the Ming Dynasty (my ancestors moved from Shanxi). At that time, the officers and men who stopped people from escaping cut a knife on everyone's little toe. This statement was also heard when I was a child. It is said that the legendary feeling is unreasonable! Second, that is to say, people with this tiny deformed toenail have Xianbei descent! The Northern Wei Dynasty in the Southern and Northern Dynasties occupied most of the northern region! It seems that this kind of deformed fingernail is rare in southerners, but it is especially obvious in northerners.
It's interesting to say. I always thought everyone had it, but then I saw my colleagues and friends and found that it was not like this!