Rotating around object when button clicked

Hello,

I am trying to make a player with a head and feet only. I want the feet to rotate around the pivot point when I click a button, I tried this a couple of times but the feet rotate 360 degrees.

         if (Input.GetKeyDown(KeyCode.Space))
         {
             feet.transform.Rotate(new Vector3(0, 0, -90) * Time.deltaTime);
         }

This script did not work as the feet just kept rotating slightly each time I click the button.

Many thanks, any advice would be great. This image shows how I want the object to move. The feet should pivot around the head at 90 degrees, and then return back to ground once I let go of button.