Occassionally, stretching my leg out and then massaging the area behind my knee, I get a pain that feels almost like a nerve being pinched. After massaging it for a while, I eventually don't feel the pain. Soon after, bending my leg and then massaging the same place I'll feel it again.
The pain is very sharp and almost "pulses" with a fading-out pain, lasting for merely a second or two.
It doesn't happen during normal day walking, running, etc. Only when I massage my leg.
The exact point is on the inside of my left leg, almost behind the knee, but more near the medial collateral ligament.