Home plate crashes

[roadking]

I've had two occassion this week with home plate crashes.
In both cases I did not see deliberate contact.

In first case, catcher has ball in front of base path (blocking plate) runner comes into plate in a non sliding defensive manner, lots of contact.

Second case, catcher waiting to receive ball in front of plate. Runner attempts to slide, but feet stick and body moves foward. Lots of contact. Runners on bases all advance.

What do you guys have here an also I'm looking for any rule of thumb advise for crashes at plate.
Thank you