More often its general soreness that would last for a couple of days but every now and then its worse and I'd describe it more as pain on the side of the knee with the soreness moving downwards to underneath. I've been running outdoors on paved surfaces all through my 20's typically about 3 to 5 miles. I'm in my early thirties now and I think all the grind may have caught up to me. I've been told a lot of things such as not warming up properly to never run on hard surfaces on a daily basis. Ever since I started using a treadmill, problems went away for the most part.