Why it is not possible for humans to runs up walls

Why can't a person just walk or run up a wall? What is keeping them from performing this task? Which formula, would best describe what is going on?

© SolutionLibrary Inc. solutionlibary.com 9836dcf9d7 https://solutionlibrary.com/physics/astrophysics-and-atmospheric-physics/why-it-is-not-possible-for-humans-to-runs-up-walls-2r7

Solution Preview

...rce perpendicular to the contact surface.
So, in order to provide that force, you would need something that can at least keep your feet on the wall (magnets? vacuum? hooks?).

But that is not the only problem: there is also a torque!
If in the picture the 2 forces are of the same ...