I dropped my iphone whilst it was on low battery and now it keeps turning on and off?

I've plugged it into charge and it turns on and says to connect it to itunes so I do and then the apple logo keeps flashing on and off?
I've tried restarting it but it hasn't seemed to work.
Any suggestions?

You might need to remove the battery and put it back in, I think you need a specific set of tools to do so.
If it doesn't work, you're going to need to replace the battery completely