answer:Ankle. I have a bad left ankle I have sprained severely 3 times over the years. Extreme pain and it pisses me off to no end when I can’t walk. The last time was boarding a plane for a 13 hour flight to Asia at SFO in 2010. It was so fucked. lol I could barely get my boot off before the swelling got really bad, no way to elevate it and sat for 13 hours with a soggy bag of ice water on it on the plane, then limped through Taipei airpot in my sock. I was in so much pain and so damn mad. haha