While the southern version of shin-kicking is a rather gentle sport, with soft shoes, where the aim is to wear down the opponent with the kicks and then wrestle them to the ground, in the north of England, where it is called "parring", (often pronounced "purring") it is a very different sport; Brian's doctored shoes would have been considered tame.
Parring involves shoes with steel toe caps, metal plates attached to the sole, blades or even nails attached to the toes.
"Corrugated shins" from bouts are a badge of honour.