You must have a safe way to access a scaffold over feet.

2 feet

Explanation:

One of the basic requirements of scaffolding is that access must be provided when the scaffold platforms are more than 2 feet above or below a point of access.

Therefore, you must have a safe way to access a scaffold over 2 feet.

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .