To make things clear, let's first define what is meant by resistance or obstruction to a public officer. To start with, a public officer can be a firefighter, a police member, a sheriff, but also a parole supervisor, park rangers, or correctional officers.
Private security guards do not fall under this category because they are not considered as performing a public duty, meaning they are usually treated as private citizens rather than law enforcement officers. Thus, resisting arrests by security guards is not a crime. Keep in mind that things might be different when resisting off-duty police officers working as private guards.
When the person in question poses a substantial risk or even physically injures any officer or a civilian, the case is one of the resistance of arrest. Such behavior may justify the use of force to overcome the resistance and the consequences of a conviction can be very severe.
Unfortunately, the law is not specific on the actions that meet the definition of obstruction or resistance. The result is that often convictions of such a crime are based on the interpretation of officers.
Actions that might result in charges are:
Fleeing from an officer
Not responding to the officer's orders
Struggling or resisting when the officer is putting handcuffs onto the suspect