Our son used to bang his head every day. Huge raging tantrums. The more we reacted the more he raged. One thing that I found helpful was limiting my response - if I freaked-out the whole situation escalated. I know that it is hard to remain calm when your little child is throwing herself backwards in a rage and smashing her head on the floor, trust me, I know. Try to prevent her from hurting herself but do not react in a huge way. This helped for us - but I stress, every child is different and this might not work for you. It did work for us.
There isn't enough info to determine if there is an underlying problem. If you are concerned have her evaluated using the Baylor test. Ask your pediatrician. This is generally given at their two year check-up but I believe can be done sooner. My child is 3 and he is being diagnosed for a developmental disorder. Wish I had seen it sooner but he was sooo smart and really atypical.
Questions to ask:
Does your daughter have back and forth communication with you through gestures, smiling, cooing, etc. Really? Try to initiate back and forth communication.
Does she respond to her name?
Does she point when she wants something?
Does she understand when you are upset or crying?
If you are concerned I would really urge you to seek an evaluation, immediately. I waited because I found so many reasons why my child couldn't possibly have a developmental delay. Sigh.
Don't want to alarm you, really don't. However, if there is anything wrong it is best to catch it now. Early intervention is crucial.
Best of luck. Hope that everything is well and good luck with the tantrums.
There was a similar post to this a few weeks ago,does she do this sat in a chair you dont say,or when she is sat on the floor, pad and cushion anything you can,I doubt if there is anything wrong with her, possibly she is trying to get your attention, have you noticed any pattern of when she does it ,is it when you are busy or on the phone or talking to someone,and it grabs your attention.that could be her trying to get it.Think of anything you wre doing prior to her doing this.