Seeing an injured knee: things will take a turn for the worse.
If the knee is swollen: vou don ‘t know what to do next. Seeing someone else kneeling: you have wronged someone and now feel guilty.
Depth Psychology: The knee represents erotic desires, cravings, and passion. It may also be a sign of humility or even a humble attitude (particularly if you are the one kneeling). Sometimes it represents guilt for having harmed someone.
If that is the case, make amends now.
See Legs.