Plank of wood chest

Some people are so accustomed to acting tough that they forget that it is a front.
They posture and strut in a
parody of masculinity.
This is an elaborate disguise designed to hide their inner
fears and uncertainties.

Two common indicators are the plank of wood chest and walking on the balls of the feet.
The chest is not a solid lump of bone and needs to flex as you breathe.
The human foot naturally walks heel-to-toe.