Hi, thanks for writing to HCM. This is just to inform you that, it is physiological (normal) to develop a little bit of stiffness
in the knee after being in prolonged standing position for an hour. If you are able to carry out all activities of daily living without any problem, then it indicates that there is nothing wrong in your knee.
If you are still concerned, i advise you to undergo MRI
scan of the knee joint which reveals all the issues in the knee joint. Hope this helps