Hit the brakes hard. When I got ready to drive, the car would not go

I had to stop quickly and hit the brakes hard. When I got ready to drive, the car would not go. I put it in park and then back into drive, it still would not go. I put the car back into park and turned off the engine. A few seconds later I cranked the car, put it in drive and everything seems to be okay now. Any ideas? Thank you.