Hi, I was on a 12hour flight and toward the end of the flight I had a strong ach in my knee that I couldn t get rid of even after stretching my legs and walking around. It went away a few hours after I landed but felt tender still. A couple of days later I noticed a thin curved bruise across my knee cap and over the week it got bigger and more spread out and went through the blue, purple and yellow stages until it went away. But it took a week and a half to heal. I flew back again for 12 hours and my knee was fine. Should I be concerned about the bruising and could it have been from flying?