Blueberry with one single TALL dominant branch

I bought this Blueberry Bluecrop in spring. Due to my clumsiness, I twice accidentally damaged the main branches. The plant then has grown a new dominant branch from the side. But very strangely, since then only this dominant branch has shot up leaving all the other four side branches without much growth. 

I wonder if it's normal or I should have done something to correct it?