I knew some fighters. One of them was a low kick specialist and his shin felt like one solid piece of concrete. Not sure if it was fused but he couldn’t do cert

I knew some fighters. One of them was a low kick specialist and his shin felt like one solid piece of concrete. Not sure if it was fused but he couldn’t do certain movements , but he could kick with unbelievable force. I have no idea how his opponents could block this with their own shins. Many years later I still have some sensitive spots on my shins from trying to train with them. It was impossible.