knee problems

Question
Hi John...hope you can help...i'm 64 and an avid daily runner.  Have run 15 marathons in the last 10 years and am scheduled for a half marathon in a little over two weeks.  I've never had knee problems but lately i've noticed what feels like a "pinch" above my right knee when I start out on my run.  As I get warm (maybe a couple of miles) it tends to go away.  I've also noticed at night in bed if I try to straighten my leg it pinches and I have difficulty straightening it.  That's not the case when walking or running.  I'm of course very concerned because I have this half coming up (and it's out of town - have a lot of money invested in the trip) and I can run on it.  I have possibly over trained, as we runners usually do, and haven't had a rest day in several weeks.  It's not incapacitating but it is concerning.  I know I should probably have an MRI but am hesitant until after the race...guess i'm hoping i can run through it and it will go away.  The "pinch" is not in the knee but in the fleshy area just above it.  Wonder what you think....thanks (this may be outside your area of expertise, and if so, sorry.

Answer
Hi Don
I can help you with that,but with time and clarity of your situation i would like to discuss this over the phone with you if that is ok with you to make sure we get this right and you fully understand the protocol to fix it.Just go to my site for contact.I'm in Albuquerque NM and you can call now or any time.Looking forward to your response

John