I know that osteoarthritis pain is worn bone rubbing on worn bone when it is designed to rub on cartilage.
I understand the mechanisms (somewhat) involved in the soreness that muscles feel after an unusual increase in muscle use. (I have felt this most excrutiatingly when I returned to swimming after a long time away and awoke from sleep that night in near-screamworthy agony in my trapezii)
What I want to understand is exactly what is happening in my body to cause the sensation of pain and stiffness in my knees particularly, but also other spots, when I am inactive for long periods of time. I know the “meta” reason: fad, lack of exercise, age, etc. I am just interested in understanding what exactly is creating the sensations themselves.
I am especially curious about the odd feeling of extreme stiffness that develops on the left knee and is actually clustered around the back of the knee. it feels almost like there’s a balloon under the skin behind the knee that slowly fills while I sit in one position, causing soreness, stiffness, and a desire to stretch and move the area to “let the air out”.
Now, to be clear: I do not ACTUALLY swell up in any visible way. If there is a collecting of fluid of some kind, it is deep inside and doesn’t make a visual presentation.
Also, the sensations I’m describing have been happening to one degree or another for years, they are not new.
I had an ACL tear in my right knee almost 20 years ago that “healed” on its own (I’m told that they never actually heal in terms of knitting together, I never followed up on how true that may be or not.) And about 7 years ago I had a meniscus tear in my left knee, which I had surgically repaired. (Again, it wasn’t “repaired” in the sense of being put back together, they just snipped away the dangling bit, like a hangnail inside my knee. I know this because they filmed it and gave me the video. It was cool.) So while both knees have been injured, they do not feel as though the sensations are echos of those injuries. Especially the left, since the majority of the sensation is in the back and the meniscus tear was decidedly located in the front, right under the cap.
And on top of all this, I am by nature an unusually flexible person with very loose joints. Don’t know that it bears, I just thought of it because the whole “stiff” thing is so strange - I’ve never been a stiff-jointed person. (My mother’s joints were so tight she couldn’t stretch her fingers wide enough apart to lace them together at the base. My joints are so loose I can and do fold my feet in on each other when I lie down and I can put my hands flat to the floor without even thinking about it.)
So… what exactly is happening in my body that creates these unpleasant sensations?