When performing the Back Attack, Knuckles does a backwards thrust while in midair, with his elbow sticking out. This causes him to stop and lurk backwards a few feet, thereby rapidly changing his flight direction.
In gameplay, the Back Attack is quite useful when Knuckles is heading for obstacles or is about to have an awkward landing. Additionally, the move will not cancel the momentum Knuckles receives from the Boost Mode. During the startup of this move, the Back Attack can also deal damage to enemies in Knuckles' flight path. To use the Back Attack in gameplay, the player must press the R Button after being launched into midair by gimmicks, like Springs or Ramps.