i was walking just now and when my weight was on the right leg, my right knee just 'disengaged'. it just collasped and i nearly fell if not for a pillar.
for the rest of the day i felt as if my knee was made of lead. damn stiff knees.
waht is the cause ? this is the first time my knees 'collasped' so badly. other times it's a mild slip,
I think you may have the arthrosis of the knee and damaged ligaments which don't hold the knee in the right position.
If I remember well, you have complained about your knees also before.
Have you seen the orthopaedist? You seriously should visit him/her. If you do nothing, it gets worse and you will have to wear knee braces to stabilize your knees. www.donjoy.com