50 to 60 G's would make your head feel like 200 pounds. A sudden stop in a car can generate about 2 G's at most.

Think of putting a 200 pound weight on your hand as it was on the floor. Your hand would feel smashed.

A concussion would have some immediate symptoms that may increase over time. A struggle to focus, think, balance, and many more.

In football, there is an injury called a sub-concussive impact. These are the frequent bell ringers from helmet to helmet hits and such that last only a second. It takes hundreds of these in a month or two to accumulate to damage.

Remember, Correlation does not mean causation.