I did that playing volleyball. i jumped up to hit the ball and lost balance. my glasses flew off. I was down for about 10 Min. The people on the other court came running over. the bang my head made was very loud sounded like a bowling ball hitting the floor. I was sort of shaky and my ears were ringing. I drove home seeing double. it hurt to raise my neck for 3 days. about 4 months later i did the same thing again on a parquet tile floor solid concrete.
I did that playing volleyball. i jumped up to hit the ball and lost balance. my glasses flew off. I was down for about 10 Min. The people on the other court came running over. the bang my head made was very loud sounded like a bowling ball hitting the floor. I was sort of shaky and my ears were ringing. I drove home seeing double. it hurt to raise my neck for 3 days. about 4 months later i did the same thing again on a parquet tile floor solid concrete.