A friend of mine, female, age 66, has had burning leg muscles and collapsing at her knees for years. She has had many tests and several doctors including neurologists. No one can seem to diagnose her. B12 is normal. She has fallen and broken her wrists. Today she nearly fell man times because of her legs giving out. Pinched nerve has been ruled out. She has a small frame, tendonitis of the elbows, eye problems inc. pre glaucoma and some kind of flaking in the eye. She nearly died from a clogged bile duct. Also has some arthritis and hyperactive. These are the things I know about her physical health. Any ideas?