Rock Attack was an early obstacle in the event known as Power Island held in Kinniku Banzuke. The obstacle revolved around competitors having to stop a 50kg ball that was 2.0 meters in diameter from rolling down a steeply inclined slope, and then push it back up the slope to reach the next obstacle, Rock Valley, which directly follows from this one.
The obstacle's concept had previously been used in the event Strong Papa, even reusing the same prop, albeit on a steeper slope.
Major controversy however, surrounds the obstacle; the steeper slope and heavier weight, along with the lack of safety gear, created a much greater hazard to competitors attempting it. In fact, one competitor in particular, Isa Takunori, had the heavy ball crash against his head and foot at the same time, making it almost impossible to have a cushioned landing, which he described as being "blown away". Isa's injuries were severe, and he was permanently paralyzed following his failure on the obstacle.
The injury and inherent risk to the obstacle's concept would ultimately lead to the rebranding of Kinniku Banzuke. However, the concept of pushing a heavy ball up a slope, albeit from the bottom-up rather than having to catch it first, would eventually be revisited via KUNOICHI's Cannon Ball.