knockdown + stonefist gaunts

does the increased knockdown time from stonefist gauntlets apply to just attack skills, or also spells and the like?

Stonefist gaunts will affect all of your hammer knockdown skills except Backbreaker (which is why the skill is garbage on a warrior primary). They also do lengthen the knockdown time of spells, but cannot be longer than three seconds (in the case of gale).

many thanks