Armor lock

Armor Lock is an Armor Ability in Halo: Reach. When in this mode the player is invulnerable to all damage, but the player also cannot move. Along with this, when the Armor Lock is activated, it will shed stuck Plasma Grenades and Needler rounds. It too will emit a slight EMP when in use. Armor lock can be charged up in three stages, with each stage inflicting a stronger EMP and pushing opponents farther away. Armor Lock is only available to Spartans. If your shields or health have taken damage before activating armor lock, your shields will not recharge and stay at where they were until after you have finished using armor lock. Once you have finished, your shields and health will be at where they were when you activated the ability and will then recharge normally. This is a slight disadvantage to an otherwise very powerful armor ability.

Animation
The animation for Armor Lock is a Spartan, punching his fist on the ground. In doing so, his shields will look like they are about to burst. The Spartan will remain in this position as long as Armor Lock is active.