I Am 85 Years Old And In Very Good Health

I am 85 years old and in very good health (diabetic). I was walking about 4 miles a day and traveled a great deal until about 3 years ago when I developed aching in my right thigh (pain is too strong a word). I really need to get back to my walking as I have a lot of trips waiting and I don't want to end up in assisted living!!!!!!!