Quote Originally Posted by Neo
The little shockwave you see coursing through Titan-Eren is from his own punch and afterwards his own hand is destroyed. Sure it heals right away but it really does show that physically the Titan's don't have a lot of defense.
The "shockwave" depicted came from his neck and spread down his body, which didn't make any sense to me. I would have imagined it as kinetic energy coming from his toes, through his torso as he twisted then through his arms to the decapitated head - but that didn't happen either.

No idea what the "wave" was. DS thinks it's some sort of reinforcement mechanism.