I have weird knee pain.?

Everywhere I've gone to look up knee pain, it always is talking about the joints, and my pain is in the muscle connecting to the knee cap.

I've had this pain since I was 10 (I'm 15) and I know it's not joint pain.

Here are some additional details:

It hurts really bad to sit in a car (Vehicle) for more than 30/40 minutes

I sometimes can't bend my knees down all the way 'cause of the extreme pain

Sometimes if I've been sitting on the ground I can barely get up because of the pain.

I'm NOT overweight (I've been considered underweight, I'm 5'4" and I weigh 107 pounds)

My arms/toes/fingers/legs are long in comparison to my torso.

I'm not taller than the average 15 year old.

The pain in my knees seems to calm down if I don't eat any gluten (flour, wheat, weird cereals, etc.), sugar, bad stuff like pizza and fast food.

I'm also considered "Highly Sensitive", if that could have any connection to my weird knee pain.I have weird knee pain.?
It could be Osgood Shlatter condition which is common in teens while still growing. I have it as does one of my friends.



More info http://www.webmd.com/a-to-z-guides/osgoo鈥?/a>