My foot is numb on the right side between heel and big toe if i try to rub it it feels like an electric shock in my foot why?

Nerve irritation: There most certainly is a nerve branch that is being irritated. This is a classic finding when you get "electric shock" sensations. See a podiatrist for an exact diagnosis and treatment.

Nerve entrapment: Sounds like a nerve is being traumatized by surrounding tissue. This may be the result of inadequate foot support or possibly from higher up, even the back. See podiatrist.