I am 78 and was diagnosed with orthostatic tremor 8 years ago by a Movement Disorder Neurologist. It is a rare neurological disorder ( in 8 years I have never met anyone else with OT!), characterized by high frequency tremors in the legs. Standing in one spot is so difficult and feels like I will lose my balance. Walking is better, although that has become more difficult over the years. Many doctors have never heard of it, and I had to "educate" my primary MD, my headache specialist, and my endocrinologist about OT after I was diagnosed. A good source of information is http://www.orthostatictremor.org. It is truly a difficult disorder to live with and misunderstood by many. I tried meds for 3 years, but they did not help and had too many side effects.