So... I haven't trained in some time, partly financial, partly physical, partly life circumstances. Boo on me.
The initial injury that stopped me from training was what I believe to have been a strained MCL (didn't go to the doctor. Boo on me.).
We were drilling a newly introduced attack from side control, zero resistance, I was uke. So, essentially, I was on my back doing nothing. I felt a sharp pain like a cramp shoot through my knee, which I thought was odd, there not being muscles in the knee. Finished class without issue. When I went to stand up, however, I had serious, heavy limp type pain in the inside of that knee. It ended up taking months to return to normal, would have easily kept me from training for three months (at which point the pulled back I got painting my ceiling took over).
We did knee circles as routine warmups. It never seemed stressful in the least, and was described as a warm up, and not a stretch, just utilizing the range of motion prior to loading the joints.
I guess, in retrospect, I wonder if repeated knee circles had introduced minor injury, which then let go with little provocation, the same way abusing your back can result in blowing out doing something innocuous later?
Anybody familiar with this line of thought?