I fell mountain biking and cut my knee open on a rock. Turns out I partially severed the tendon in my right knee. Of course, I didn't know this until I got to Burnaby Hospital and they examined my knee. The doctor told me tendons are like pieces of paper once torn and I could easy have completely severed it by driving myself to the emergency! Great care by the staff on duty and my leg is pretty much back to normal now. Except for the scar.