Video: Instructor’s video
Description: This demonstration shows that even with an additional force (hitting a cinder block), the pressure of the nails is not enough to puncture your body.
For effect you can hit the brick a few times with a wrench.
Note: Be very careful when using the metal wrench. Only a slow motion is required to break the brick.
When using the wrench, hit the brick off center where there is less material so it’s easier to break.