Yes, ostriches are big and have powerful legs, plus they can have really mean looks on their faces.
If one attacks you, here are the very simple things you can do.
Don’t run. It can out run you…
Raise your hand higher than its head. It will think you are bigger and taller.
Stop it from moving by pushing against its chest. Not sure I like this one, since an ostrich can weigh up to 300 lbs. But then again, it isn’t really balanced for pushing like a human is.
Or you can get it into the vampire mode and suck its blood, like in the picture below.
This is an excellent video. But it disagrees with the approaches from other “ostrich attack” sites.