Knee Pain

Hi knee pain people.

For the last six weeks, very occasionally I have been getting a twinge on my right knee. I've just ignored it because I've never experienced anything like that before. Haven't changed the setup on my bike recently... if ever really. It hasn't caused any issues other than yeah, an occasional twinge of pain, usually when getting out of the saddle. I'm used to a lot of miles (300-400km a week) and have never experienced any overuse injuries before, so yeah, I ignored it.

Last week I did a couple of big rides with some smaller ones in between. No pain during any of these that I can remember. The second Big Day was really fucking hot.

A couple of days later I'm experiencing knee pain - where I previously got the very occasional twinge. It hurts when getting up from being sat, almost like it might burst? I can't feel it while walking or otherwise moving about.

Yesterday I fling my leg over my bike for the first time since last Thursday to see if it hurt while riding - oh boy. Couldn't pedal with the affected leg. Every rotation gave the above mild feeling of bursting. There is no swelling that I can tell. The affected area - right knee, inside, slightly above kneecap - isn't hot to touch. I've been foam rolling various parts of my leg, and also stretching, as well as icing the knee a few times a day. There's not been any improvement really since it started hurting on Friday evening.

What the hell have I done? I've not changed anything on my bike. I've not suddenly vastly increased how much riding I do (though granted, a 300km followed by a 200km might be pushing it, but I've done more than that before without problems). Am I just getting fucking old?