I came first in a 100 metre dash without warming up. I did the 200 metre dash and came second after doing the 100 metre dash. Now in comparison the 100 metre dash would of been like a warm up so really it is not true that warm us do anything.
Are you sure you didnt get the injury because of growing problems? If you are of that ages, sports become harder to do around puberty because you body e.g. bones and muscles are growing and sports seems to go wrong during it.
I find warm ups pointless.