I know it's more MM field of expertise Primate. But how about truck axles for jaw strengthening? Or would the softer truck tyre be better for jaws?
so you take a noob whos shins are untrained, and half swing a baseball bat at them? whats step two in your plan - place your legs under a steamroller?
We had one student in our dojo who wanted to cross train and he said his shin is made of iron from all the MT training. The instructor, Bill Schettino said let me try to hit it with a baseball bat to see how hard. Shut him the **** up.
i have seen a homemade canvas bag filled bamboo sticks (sticks same length as bag). the idea is the more conditioned u get the more bamboo u put in.