What happened with me is I had a scab on my knee (running on sidewalk with my dad, he accidentally trips me, got a really bad injury on my knee that actually did leave a scar) and I bumped it hard on the gym floor (not very soft, y’know) which opened the injury and well, broke(?) the scab, which hurt like a mf. Pants ruined. The entire side was covered in blood, had to throw it out and buy a new pair (since it was school uniform).