I have taken these from the link above incase some of you have problems getting it to work, I hope this is relevant
Myth -Thai Boxers deaden the nerves in their shins by rolling a glass bottle up and down on their legs.
Fact - this is completely false and should not be practiced by anyone. The so called deadening of the nerves (or worse removing of the nerves) is simply not true. Nak Muay spend hundreds of hours doing repetitive kicks on heavy bags, pads and nearly as many hours sparring with a partner. This repetitive training familarise the boxer with pain, and raises their pain threshold in any one particular area (i.e. the shin). This in turn may give a sense that the nerves are deadened, they are not, they are simply a little dormant. Stay away from training for a long period of time, and see how your pain threshold will have dropped when you next clash shins.
Myth - Thai Boxers harden their shins by bashing their shins with a rolling pin.
Fact - this is completely false and should not be practiced by anyone. Although shins seem hard, they are living tissue and will give a little under impact. However rolling pins are very solid and give very little in way of leeway, so continuously hitting your shins with a rolling pin will cause them to become traumatised, resulting in possible non reservable damage such as cancer.
Myth - Thai Boxing can give you cancer of the shin.
Fact - this is completely false and although the continued improper bruising and damaging of the shin may in the long term cause cancer (see above), correct training methods and proper conditioning will reduce or eliminate this myth completely.
One thing that we can not be certain of is the future of one's body, as there are far to many possibilities, such as contagious and hereditary diseases, however we can reduce the risk of any additional un-reversable damage to the body by training safely!