Try:
- How Do You Stop Pedometer From False Step Counting? - #2 by Aarush_Kumar with the Pedometer control.
These posts pertain to using the accelerometer as a pedometer with Blocks:
edit: Detecting a change in movement state after a fall is discussed here Lack of moov with accelerometre
Pedometer control source code: appinventor-sources/appinventor/components/src/com/google/appinventor/components/runtime/Pedometer.java at 83eb64a98cf2f7bb7860c9bd21169e2b22f59e33 · mit-cml/appinventor-sources · GitHub