I fell down like stock market plummets

First time ever... I fell down during my normal routine - JOGGING. The best thing is I fell on my normal route. I have been jogging there since nearly two years ago. I was with another 3 friends whereas bro and another friend were far unseen. We jogged in a pair side by side. Somehow, I stumbled and fell on the pavement. Immediately, center of graviti took over, I have open wounds & bruises on my knees. Ok.. blame on the terrain, my clumsiness and the darkness.. Afterall, looking at it now, it is not that serious.. just few red patches on my knees and hand :)