Why do I get this bruise under my knee?

[thepiedpiper]

Knelt down the other day and below my knee hurt briefly until I got up again, woke up today and there is a bruise the size of my kneecap under my knee. This isn't the first time this has happened. It isn't painful, just wondering why?

Do you spend a lot of time kneeling?

Hello oldLadyKnowsNothing, No, not really, I do sometimes sit on my haunches, but not often.