Help me. I have growing pains (if you didn't notice the topic heading and just clicked mindlessly). Within the last month or 2 I have grown from the smallest in the family to the tallest. In the process I have some real ugly stretch marks on my knees. But here's the main problem: Whenever I run my knees hurt badly. I can hold a horseriding stance, squat, kick etc. perfectly but it's mainly tuck jumps and running that hurt it most. So waht do I do? I've tried taking cod liver oil but it has no effect.