What is balls to the wall?

"Balls to the wall" is an expression primarily used in North American slang that indicates a situation of extreme action or maximum effort. It is often used in the context of working or trying extremely hard, going all out, or progressing at maximum speed or capacity. The phrase is believed to have originated from the aviation industry. In older aircraft, especially military planes, the throttle levers had spherical tops, and pushing the throttle all the way forward would bring these "balls" close to the front wall of the cockpit, thereby maximizing the engine's power output. The expression has since transcended its technical origins and is used more broadly to describe any intense or high-effort scenario.

In addition to its idiomatic use, "Balls to the Wall" is also the title of a well-known heavy metal song and album by the German band Accept, released in 1983. The song, a classic in the genre, also features themes of rebelliousness and defiance, which align with the high-energy connotation of the phrase.