Backstabbing the same as front stabbing?

hey i was just looking through the skill pages and trying to figure out if i want to be a dark avenger or a pali but then i stumbled over a skill that says "increase defence from all sides" ths skill is aegis stance at lvl 43 for pali. So my question is, does that meen when im fighting someone or a mob, i do more dmg from behind and have a lesser chance of beeing blocked or missing? (i'm not asking directly about skill, and nothing at all about class)

Critical chance is higher when attacking from behind. But this doesn't matter for a tank. As far as I know a shield blocks only frontal attacks. Block means that the P.Def of the shield is added to your own. There is also a small chance of full block (Excellent Shield Defense, 0 dmg).

The skill should allow you to block attacks from all sides.

k thanks