Is there any technical reason for this?
1 Answer
It depends. The best answer is that it's traditional to wear them.
Apocryphally, it is supposed to harken back to a custom where mothers would give their sons, who were going off to war, good-luck charms which they made from cloth torn from their own surong.
In more modern times, they often denote accomplishment and rank within a Muay Thai organization.
