So… apparently, the phrase “take an arrow to the knee” is old nordic slang for getting married.
The Findings I have been at this for a solid three hours and have turned up absolutely nothing. I did learn a lot about women in viking society as a whole, and while they were generally held in relatively high regard for homemakers, it was unlikely that they were held so highly that men would see marriage as something “crippling” as the arrow-to-the-knee joke suggests (assuming, of course, that Skyrim is a historically accurate game that just also happens to have magic and dragons and werewolves and whatever else on the side).
Based on previous research into similarly dispersed urban legends, here’s what I’m thinking happened: a funny, deadpan “what if” joke came into somebody’s mind. “what if it’s code for something?” From there, the joke morphed, and as it got passed along in the great global game of Telephone that are jokes and urban legends, someone misheard that “what if” and it became a “did you know.” But the spread didn’t stop there. It just kept going, because it made perfect sense – it’s ridiculous to think that all these NPCs wound up being shot in the knee with arrows and it’s a little world breaking in an otherwise extremely immersive game lauded for the work put into it. But it’s easy to forget that the “arrow to the knee” phrase is no more or less common than any of the other stock NPC phrases seen throughout Skyrim, and that “arrow to the knee” was just that: a stock NPC phrase, and certainly not something that was ever said by Norse people historically.
Of course, this isn’t to say that perhaps in the mythos of Skyrim, a land where magic exists and a human can be part-dragon and also a werewolf and shouting loud enough can knock someone unconscious, “taking an arrow to the knee” is used as slang by men and women to speak ill of their homemaking spouses while they yearn for the good old days of being adventurer like yourself. And just like that, you have another (or maybe your first?) head-canon.