i'm 70 years old, tookecho treadmill test 3wks ago,been hiking and campingin mountains ,yesterday i took nap for 1-1/2hrs. rotated my legs upward to get out through rearlift door of van balance way out of wack,hquthought maybe an eathquake,can drive symptoms subsided,walking taking pictures but notice balanceeffect when i get out of car sometime today