My grandma fell over on a walk on some jagged rocks and split her knee real bad to the point her muscle was floppin out of this 2cm wide gash. I was only like 10, so I couldnt do much other than help her standup and and get into a sitting position with her knee facing up. Fortunately it was just off splitting any big arteries. Also fortunately It was a fairly busy track and someone helped apply pressure to it and called an ambulance. She had to be stretchered about 50m back to the road and had it stitched up. The whole time i was never never scared/stressed oddly but I haven’t a clue what I would have done if the circumstances where slightly worse.