I've been dealing with knee soreness for a long time now. I don't know what is irritated, or what the specific cause is (certainly 'overuse' would apply here). Recently a few things have come together to suggest that tight hips might be the root cause. At this point all of this may be a misdiagnosis, but I'm just looking to try out some suggestions that sound promising.
The soreness is generally mild, it never causes me to limp or show any kind of visible swelling. Two things seem to make it feel worse:
1) Extreme running - Long bouts of running long and/or hard
2) Extreme rest - Lounging around on the couch
Things that make it feel good include simple sane activities like walking, biking a few miles, or yardwork.
The soreness makes me feel uncomfortable while sitting, sleeping, running, etc., so pretty much most of the time. Worse than anything else is how it weighs on my spirit by making all future running endeavors seem like a bad idea.
Each knee 'pops' only once if I hop on a bike and pedal a few times. Or if I walk upstairs. This occurs every morning, and a few times throughout the day. Also at times there is a mild crunching or creaking in my knees when I bend them. I suspect the soreness is a result of whatever friction causes this creaking, which over time causes irritation.
It's difficult to pinpoint the location of the soreness, except to say that usually feels like it occurs deep within my knee, right in the center there. At times when it's the most accute, soreness appears on the inside of the knee, which as I understand it suggest s that it's not IT-band related.
Sometimes I notice that my knees want to bend inward while I'm running. It's very slight, but my knees sometimes knock together, and feels related to the soreness on the inside of the knee. It's as if the inside of the knee wants to collapse just a little with each step. We had a coach in high school with knees that bowed inward pretty badly while walking, it feels kinda like the very early stages of that.
My upper leg muscles seem very tight. Not in a stiff-legged way, but often times the muscles don't feel like 'flesh', instead the feel like thick leather, or to exaggerate a little: almost like rock or metal.
I've come to look at the knee as not a 'thing'. The knee is a void between your upper and lower leg. So the cause of knee soreness is not the knee, but everything around it: the upper leg, lower leg, feet, hips, etc.
I usually do yoga at work once a week, and our really excellent yoga instructor R, keeps encouraging us and me in particular as an inflexible runner, to work on 'hip openers', suggesting that it will work wonders for running. Being stubborn, I'm not easily convinced, and the anatomical whys and wherefores are all too complicated for me to wrap my head around.
I was talking to H who has been feeling perhaps similar pain in his knees. He went and saw a doctor about those knees. The Doc probed his knees and said,
"Where's it hurt, here?"
"And what about your ankles, does it hurt here?" (probe probe)
Followed by an explanation that what happens to runners who run too much without giving the body a chance to keep up. He said that the hips gradually get tight which affects the biomechanics of the legs. An inward tendency starts with the hips and works it's way quickly to the knees and the rest of the leg.
I find it interesting how well this resonates with how I've been feeling as well as the recommendations from my yoga instructor. Putting it all together, it seems that maybe the 'hip openers' R has been pushing are worth focusing on. For the most part, this includes three yoga poses:
Knee to Ankle Pose - Second pose in the video
R's Yoga Studio - We are very lucky to have her instruct us once a week, highly recommended