Hi, i have recently been getting what i think to be night cramps. I wake up in the middle of the night with a serious pain behind my knee. It's happened 3 times this week, the most recent two ive awoken yelling due to the pain. Ive been looking around the net and found that its really common and the pain goes away quickly after stretching out the muscle.

Mine does not. It hurts to walk or even bend the whole day. Is this normal. I should prolly add that my knees hyperextend backwards by about 15 or so degrees.