I had one of these alerts go off once from my watch. After a really hard fall from tripping during a trail run. I still have the scars. The alert said: “You ha

I had one of these alerts go off once from my watch. After a really hard fall from tripping during a trail run. I still have the scars. The alert said: “You had a hard fall and stopped moving. Press this button or we call help” The “stopped moving” part seems like the perfect proxy here. People in a car crash experience a huge spike in G-force once. Then it stops. Or maybe it goes for a few seconds if you’re rolling down the highway. Car crashes don’t go on for minutes upon minutes. This seems like something a machine learning algorithm could handle. At the cost of calling 911 3min after a crash instead of 3sec. That’s still much faster than how long it takes people to call for help.