Fuckin functional.
The EMg is not a good tool to measure the time a muscle is under load, this test appeared to had just measured the stress at one point 90degrees it does not measure the force or the "foot-pounds" throughout the range of motion.
As I've stated over and over to you numbskulls there are much better, safer and more efficient exercises that you can do to strengthen and improve the flexibility of the hamstring.
The "razor" thing is just another stupid gimmick.