Fall Detection

That truly sounds unusual that it would detect driving as a fall. I've certainly not had that happen before. You can try creating a backup of the watch, then restoring it to that backup. That is done by unpairing the watch, which creates the backup, then erase the watch and restore it. Unpair and erase your Apple Watch - Apple Support

It should be working. If you entered your age in the Health App it gets turned on automatically for Senior Citizens. Check out this link....HT208944

If you still have a problem, click on the "Contact Support

link at the upper right side of this page.

How did you fall? How fall detection works is based on the accelerometer in the watch, and the motion before the fall. It is very difficult to test the system, has it ever worked? See this about Fall Detection, Use fall detection with Apple Watch Series 4 - Apple Support

I'm not sure if Apple has anything for testing the system, but you can make a Genius Bar appointment at the nearest Apple Store if you wish to have it checked.

It is not up to me to determine usefulness, however I would certainly contact Apple about that, and have the watch checked. No one here works for Apple, however outliers like yours, where there is a severe fall and no detection are things that Apple would probably like to know about. I would make a Genius Bar appointment to have them examine the watch, and you can share your experience with them. You can also share it with Apple using their feedback page here, Feedback - Apple Watch - Apple

If you are under 22 years of age it will not work.

Okay. I've not fallen with mine, however I have had a couple of false positives. One I was kidding around and slapped my left hand down on the counter (I wear the watch on my left wrist) and it was a positive, and the second was just a week ago. My wife bought a new side table and I was putting it together and there were wooden dowels that held the two pieces together and I it the one side hard to seat it with my left hand, and again a false positive. I think they may need to look at a way to fine tune the settings to do a little better job at detecting it, but I'm afraid at the same time it could lead to more false positives. Good luck.

My Watch4 has been giving me fall detection several times. It just did it while I was driving after I made a U turn. Had to pull over to say I am ok. What if I was on the freeway? So do I need to take it off my wrist while driving? I'm 66. Maybe I should turn off the fall detection? How?

I would take false alerts ANY day over no alert on a hard fall.

I fell last week off my horse - hard enough to break a vertebra -- no alert. How is that useful???