Rather like pins and needles, or as known medically:paraesthesia Fizzy legs is a prickling sensation felt in the legs after sitting in the same position for long periods of time. However, unlike pins and needles, fizzy legs may cause the person to be so uncomfortable that they are unable to move their legs at all until the symptoms of fizzy legs have passed. It may also cause extreme pain if the leg is touched when an attack of fizzy legs occurs.
"I cant move at all, I've got fizzy legs"
by Jim Smythe March 01, 2013