Is it normal for 7 month old to swing arms like she has no control over them?

I know this is a weird questions but I am curious. My daughter is 7 months old and this has been going on since she was like a month old. She plays on the floor alot and sometimes when she is on her back her she swings her arm and hits the floor. It looks as though she doesn't have control over them. It happens more frequently when she is tired. She uses her arm just fine. She can grab things and switch objects between hands. I don't know if this is something all babies do or if I should worry? Has anyone experienced this?Is it normal for 7 month old to swing arms like she has no control over them?
i think that is normal, both my daughter did that.Is it normal for 7 month old to swing arms like she has no control over them?
Completely normal, my son use to do this but now only moves his legs like crazy.


She is dicovering and learning control, don't worry.