Maybe, it overall is just a guess though, tried to use knowledge on biology to take a guess
It could work? But the bones allow for stability even when broken.. without bleeding in the area
So I'm unsure if the alien blood reason could work,
It's like if you break a tendon in a person's ankle, they can't walk without it.
Potentially the bone fracture is more like. A stress fracture? Not having broken the bone/snapped it, but caused enough damage to leave it extremely painful to attempt to support ones self on it?
