Re: unusual seiza problem - pain in BACK of knee
This RN is going to play devils' advocate here and say MRIs are not the end all-be all. For one thing, a LOT depends on who is setting up the machine parameters and telling it what to do and then on who is reading it. Often the MRI suggests one problem and the arthroscopy reveals a totally different problem
Then there is the fact that there can be a disparity between a clear abnormality and the actual source of pain. This has been proven in the case of back surgeries (poor to no actual correlation between abnormal back scans, bulging discs, etc and the actual pain, so surgery often results in no improvement in symptoms)
And again as has been said, people like to share anecdotes, but your pain behind the knee may have nothing to do with their meniscus issues and is certainly not a quadriceps issue.
I DO think seeing a sports medicine doc or at least a good PT is the next step