I get this too...though it can affect different areas at different times and it tends to be in my right foot the most. There are just times where I cannot control my limbs at all. I had to work very hard in physical therapy to regain control of them after my spread last year (gosh...it's almost been 2 years since the spread).

Do you walk with a walker at all? I have a rolling walker and it helps me a LOT with things like this. I have a much better walking gait with the walker than I do without. This was especially helpful when I was doing physical therapy to get walking "normal" again. Might be worth looking into. Without the walker, it would not be safe or possible for me to leave the house, be out in crowds, and away from a comfy couch to sit on. Also good is that the walker has a seat so if I DO need to sit down and rest while out there is always a chair with me.