Knee-trembling

A terrible, knee-trembling wash of terror ran down his spine as he lifted the gun and pressed its cold metal to his chest.

Source: wiktionary

An example: say Lyndon Baines Johnson had gotten wind that he was being trashed by some Capitol Hill minnow, chances are a single phone call from the Oval Office would have been enough to induce a knee-trembling silence.

Source: wiktionary

One ship's captain remembered Blackbeard as 'a tall, spare man' - an unembroidered eye-witness description that supports many knee-trembling references to a giant of a man, a devil in disguise.

Source: wiktionary

Her knee-trembling, heart-pounding fear of thunderstorms was no match for her fascination with the light show offered by the sky.

Source: wiktionary