The best way to avoid injury is to always work carefully. When you're tired or sick or something cramped or is sore, tread very lightly in class. Those are signs you need to focus on proper alignment, on releve-ing and plie-ing gently and within your own body placement.
But sometimes, none of that is present and you feel great about dance, great about your body, and you're all warmed-up and want to jump higher and longer and not rest and - wham! You're on your butt on the marley.
Recently two of my students were injured, not at the same time or even in the same month but rather doing the same thing: grand allegro. This is the last big jump of the class, when you're the warmest you'll be all class but also you're most tired, muscle-wise. Even if you feel like you have all the energy in the world, your muscles are about to give up. Be most careful now!
In both instances, the dancers were very enthusiastic and energetic about the allegro and they wanted to try it "one more time!" before ending the class. They each slipped, tripped, and twisted. Quickly they got off the floor and raised their feet and we got them ice as they rested. I gave them Advil for the swelling and advised them to rest a while and not hurry home until they were ready. I also taped one student's ankle before she drove a half-hour home so her foot would be in a more stable position.
The quick action helped both of them and they were able to come back very soon after their injuries, albeit more cautiously and wisely!
RICE-A. Remember it. Use it. Be an exuberant yet wise dancer and you will dance a lot longer!