How does dash attack work?

[Miryafa]

I thought Sheik attacked in front of her until the other day. Twice I dash attacked but got grabbed by my opponent (Ness doing dash+grab) instead of hitting him. I looked at the frame data for melee and the hit boxes are actually behind Sheik (when her arms go behind her) - is that the same in PM?

 

[Ethireal]

Yes. The frame data for dash attack was unchanged