Karate fighters dont codition their hands for breaking bricks by striking pillows or pads! Fighters in southeast asia bang their shins together for fun, like Americans play bloodyknuckles. With this in mind, how is kicking thai pads or a heavy bag going to condition the shins for a collision with another persons? Im not saying kick or beat your shins forcfully against hard objects at first, but to gradually condition them. Someone will kick you, and they will be hurt.