This happened at least 5 times in the last 9 to 10 months. I feel a weird sensation in my legs which causes loss control of my legs and I had to literally fall on the floor with pain ( cannot pinpoint where the pain is coming from ) but I feel there is a rush of blood to my legs and once I fall on the floor blood rushes back to my head. I had a ultra sound done, doctor thinking might be aneurism in the stomach or Pelvic area, results came clean. I do not experience any headaches or dizziness at all. I am perplexed. I am wondering if a pinched nerve in the lower back might cause something like that. I would appreciate your advice and your thoughts as to what this might be. thank you.