I'm new on the boards. I found this while searching for information about my increasingly frequent knee pain. Basically, I run 1-3 miles, three times a week and afterwards climbing/descending stairs is painful. Not only does it hurt, it gives out completely. I've fallen twice in my local gym and BARELY caught myself on the railing.
Aside from stairs, my knee is fine. I haven't noticed the pain when doing squats, but i haven't done many squats since it began - I don't want to press my luck.
Anyway, the gist:
What: Sharp knee pain/failure
When: Climbing/descending stairs (descending is worse) after running 2+ miles.
Any insight would be greatly appreciated.