And...marathon training is derailed

OK, so we have a "fastest kid in 5th grade" running race every Friday afternoon at recess. Today a kid comes running at me full speed not even looking at me (although freakily he's looking right at me). He plows into me and I knock him down. He's about 90 lbs and solid bone and muscle. He badly rammed my kneecap and my left knee is killing me (yes, the same left knee that I injured 4 years ago and have rehabbed back into shape). Grrrrrrr.... dang kid not paying attention. There'll be no running for awhile. Bah!