I am an avid runner, and had been running 30-35 miles/week to keep a base in preparation for training for a full marathon. After running on slippery uneven snow and ice, my patellar tendon got irritated. (My thougths are that the quads overwork and the feet are tense trying to navigate and negotiate undulations in ground and prevent slipping etc.. resulting in all stresses going directly to the knee).. Then, on an average day run shortly thereafter, I landed very hard on same leg fully extended into a depression in the road, which I believe may have done further damage to the patellar tendon and perhaps even a bone bruise. I'm wondering if also the acl was "bruised" or "stressed" (I know it's not as bad as a tear)...If you could help me figure out if it's tendontitis or bone bruise or the like that will help me figure out if I can back out there and continue on track training for the Boston Marathon - Thank you....