 [ Symptoms ] stiffness tightness and minor swelling on knee after exercising with no pain  i was playing soccer yesterday and i was running around and shooting like you would and for some reason at one point my knee started feeling weird there was no pop or anything i went home and then the knee started to feel really stiff and tight i can not fully bend it since it feels like it is going to explode extending the knee also feels weird there was a bit of pain yesterday a few hours after but now i feel nothing i have never had any knee problems and i am 17 what could this be [ Disease ] you might have injured your knee joint while exercising this is giving you stiffness and tightness rest to the joint and application of pain balmsspray will reduce the symptoms