Well, I was just straightening my legs after squatting down today and I noticed the oddest thing.
The top of my left knee does something completely different to my right knee when it is bent back (i.e. straightened).
Basically the part where the quads join the top of the left knee cap stays contracted right until the knee is fully straightened whereas the same part of my right knee relaxes say 10 degrees before.
This is reversed when I go to bend on my knees into a squat: the left knee muscles contract earlier and distinclty pull the knee cap up before the knee bends proper. The right knee stays more where it is.
Anyone know why this might be happening and what, if anything, should be done about it?