All military service members dread the ominous  "knife-hand" when being addressed by a superior as it usually means they are being corrected or some sort of discipline is soon to follow. Below are the 8 images designed to awaken your greatest fears:

1. Recruits are quickly introduced to knife hands

Photo: Cpl. Octavia Davis/USMC

2. A loud verbal correction often accompanies a knife hand to maximize effect

Photo: Mass Communication Specialist 1st Class Andre N. McIntyre/Navy

3. The knife hand extends across all branches of service

4. A knife hand can be used to correct a trainee's salute

Photo: Alan Boedeker/US Air Force

5. Knife hands come in handy while testifying before Congress

Photo: Sgt. Marionne T. Mangrum/USMC

6. A four-star knife hand is exceptionally attention-getting

Marine Corps

7. Even "poolies" can get a taste of the knife hand

Photo: Sgt. Jose Nava/USMC

8. There are knife hands and then there are Merhle from 'The Walking Dead' knife hands