Id imagine this uses stronger muscle groups. Think about how much force you can make pushing down with your leg, compared to moving it forward or backwards when you are upright.
I use the same method. Although when reaching into the cover to its corners, I sometimes put my head in too. I stand up like some sort of inverted-duvet covered ghost and give the dog a fright. Then I continue the process again.
It was said that it would not have been discovered had it not been modified half way through its life to spread faster. This led to it spreading beyond the Natanz facility that it targeted.
I had a similar thought. When I saw the monitors, I thought "How are they mounted to the hull? They wouldn't screw them into it...." well, it turns out they did.