Injuries are not rare at all. At all! You are speaking from ignorance, plain and simple. And you are coming off as being wholly unsympathetic to a very physically demanding job in service of your totally ill-conceived and pointless argument.
Strains, sprains, torn muscles or ligaments, vocal damage, falls, etc etc are all common. There’s a reason why chorus shows require physical therapists to be employed.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."