A lot of the time after runs, my left knee ends up hurting if I put weight on it while its bent, like in a bodyweight single leg squat. It isn't something debilitating that prevents me from walking, but it does impact me when I do something like jumping up stairs. I've found that if I do single leg squats (gradually going lower each time), it helps alleviate the pain. I've recently been upping my mileage gradually from 18mpw-30mpw, and my feet are flat but I wear neutral shoes (I tried inserts once and they hurt like hell). Under both of my kneecaps, there are slight bumps but on my left leg the bump is bigger (I went for a physical today and my doctor mentioned something about it).
Does anyone know what this knee pain may be?
More importantly, are there any exercises that I could incorporate to solve this problem completely?