because it's all about the "arts" of using head, fists, elbows, knees and feet to attack the weakest point of the rival's body. For women to become Muay Thai fighter and to entering the sport competition, there are some limitations for them, due to the Muay Thai tradition that women are not allowed to entering the Muay Thai Ring. It is believed that women in the ring will destroy boxer's ability and skills as well as against the amulets that boxers are wearing.

However,

in the modern era, the Muay Thai tradition has changed to accept women to become Muay Thai boxer and they are able to entering the Muay Thai ring, but there must be separate arena only for women and they are still not allowed to jump over the top rope to entering the ring which will represent that they are over the men boxers and their amulets, instead they have to duck under the rope to enter the ring.