Fall sensor sensitivity issues

This what information that Apple has provided in Support for the Apple Watch Fall detection, Use fall detection with Apple Watch Series 4 - Apple Support

You should see the I did not fall option if you scroll down on the watch. If not, you may wish to power the watch off and then back on again.

Also, from the support document that I linked above:

Apple Watch cannot detect all falls. The more physically active you are, the more likely you are to trigger fall detection due to high impact activity that can appear to be a fall.

1. no

2. it is not there.

3. The sensor does not know if the watch is on or off the wrist.

send feedback here and request the features you want -Product Feedback - Apple

Ditto. I'm an active septuagenarian and have had fall detection on since I installed the watch (on release day). I've had multiple fall alerts that didn't seem appropriate. Although, strangely enough, golf doesn't seem to trigger an alert, I've had it trigger using a hammer in the off hand, trigger when pushing a garden stake into the ground, trigger pull-starting a mower. Fall detection seems like a terrific idea (my doctor asks me every 6 months about falling), but it seems to have problems in implementation. First, there's no way to cancel the alert hands-free. "Hey Siri, I haven't fallen." would be a nice feature. With any ambient noise or activity in the vicinity, the alert isn't noticeable enough (except the "I'm about to call 911" feature which lights up the accompanying iPhone). There's no clue that it's learning anything - about my activity or my "I didn't fall" cancellations. The Series 4 even seems a bit less sensitive in bedside clock mode (bump it to see the time) than my Series 2 that preceded it, so why then is it so sensitive in fall detection mode? Can I adjust its sensitivity?

I'm not the human physiology expert, but it seems reasonable that a "fall" would require a couple things - some sudden motion of the type found in a fall, termination of that motion abruptly, validation that this motion happened while the watch was on your wrist, and validation that I'm in a fallen position (prone, supine, etc.). The watch seems to know when I'm standing (or not)... can't it do better to determine whether I'm horizontal or not?

I'm not knocking fall detection. I'd just like to be able to use it with fewer (all, so far) false triggers. Seriously... "Hey Siri, I didn't fall."

Use fall detection with Apple Watch Series 4 - Apple Support

As seen in the above page, I have been able to select the option that says "I Did Not Fall"

So, the answer to #2 is yes but you must scroll past the options that fill up the screen at first which I have done.

I am in the same age group. My watch has triggered fall detection three times since I had it. Once was a minor trip on the stairs. I did not know it had been triggered until I heard a faint bleep and managed to stop it sending out an alert in time. The second was not more than a sudden movement of my hand on my car steering wheel. The third was when I clapped my hands.

Two issues - one is it is too sensitive such that have to switch it off, the other is the warning to the user is not loud enough to notice, particularly in a fairly noisy environment.

Seriously, if you would like to see improvements, Apple needs to hear from users about problems. To do that, you need to use their feedback link here, https://www.apple.com/feedback/watch.html

Send feedback to Apple. That is the only method for them to understand how it is interacting with users, https://www.apple.com/feedback/watch.html