There are some Knocked Down effects with an extendable duration (unlike Prone), with no Resistance or Immunity to counter them.  Their duration increase with Int, PL, Ability Level (for them from items), Enfeebled and Dispersed Suffering, and are reduced by enemy Resolve. Mule Kick (1.5s) Fighter Skyward Kick (1.5s) Monk No Quarter (2s) Rakhan Field Boots (as beneficial effect on enemy) Run Through (4s) Whisper of the Endless Path (as beneficial effect on enemy)