Hi Gail, welcome...This doesn't sound like your symptoms are osteoporosis related, but you definitely need to see your Dr. to find out what is causing these feelings in your legs and arms, and also your knee weakness.

If you don't have insurance, you could be seen at a hospital emergency room, but your best bet is to see your primary care Doctor.  See what you can do to set up an appointment and be sure to write down all your symptoms and concerns and take the list of questions with you.  If you have a friend or family member who could go along with you, that would help to get all questions answered.  Also, include all medications and supplements, or diet changes you made recently.

Good luck and I hope you find out what is going on!