Disrupting Blow

(Tome of Battle: The Book of Nine Swords, p. 63)

Diamond Mind (Strike)
Level: Swordsage 5 (Two Diamond Mind maneuvers), Warblade 5 (Two Diamond Mind maneuvers),
Casting Time: 1 standard action
Range: Melee attack
Target: One creature
Duration: 1 round
Saving Throw: Will negates

With a combination of brute force, keen timing, and exacting aim, you force your opponent into an awkward position that ruins his next action.

As part of this maneuver, you make a melee attack. If this attack hits, your target takes normal melee damage and must make a Will save (DC 15 + your Str modifier) or be unable to take any actions for 1 round. The target does not suffer any other drawbacks or penalties. He can still make attacks of opportunity but is unable to take immediate actions until his next turn.