Task: Question Answering
Input (English): Context: I do n't get injured very often ( other than sore muscles or that bad arm / shoulder ) in terms of actually ' getting hurt ' so today marks a first in a very long time . I was running on pebbly , rocky terrain at Bartley Ranch ( that was where I took the photo of the desert mountainside ) and twisted my ankle on a rock . But it was n't my ankle that hurt ... I fell ( was wearing running shorts ) _ and just completely scraped up my right knee and side of my leg . It just looks awful and stings like crazy . 
Question: What seemed to have caused the injury ?
Output (English): They were doing some exercise .