answered Dec 07, 2009 at 05:45PM
It depends on how you define "bad knees." If you have constant knee pain, or constant stiffness, mobility problems, or flexibility problems, it can help determine what kind of treatment you may need. Remember that surgery and/or knee replacement is a last resort. The worst thing you can do for your bad knees is to sit and do nothing all day because that promotes atrophy of your thigh muscles, which is important for your everyday mobility. The exception to this is that if you have an overuse problem like knee tendonitis, then resting would be a good idea. Talk to your doctor so you can isolate the real problem with your knees so you can get an appropriate treatment.
Hope this helps!