I think I might know what you mean. I had a similar experience from using the elliptical. I think the incline on the cross-trainers at my gym is too high and so they made my knees start to hurt (during runs and other exercises) and so I stopped with the incline and the cross-trainer ad now just run on the treadmill flat. It's taken a few weeks and I now work on my leg and thigh muscles a lot more, but the pain is gone. I think from a little online research, what the problem seemed to be for me was a "knee tracking disorder" or "runner's knee." It didn't hurt enough that I was bed-ridden but just enough to make me take stairs very carefully and be wary about crawling into bed or kneeling to get something or do something. I'm no orthopedic specialist but I suspect the tracking issue was what was wrong in my case. I didn't see a specialist because the pain wasn't tht excruciating and it would have been a big deal to get that organized where I am; but if you have that option, like others have said, you should probably take it. For me the clicking feeling of discomfort in the knee felt like the knee needed to crack or pop to feel better (if that makes sense).

Sorry! And please feel better soon!!!

Thanks "toasted"...I've also did some googling and found the same. Today, I just stuck with 30 minutes (level 11) on my eliptical and 20 minutes weight training on my lower body (quads/hams only). I'm hoping to strenthen the muscles around the knee so as to remove some of the strain off my left knee.

I've considered the fact that it IS my left knee and as such, I most likely have a muscle imbalance (right handed person here!). Buoy....when I did my ham curls I could only curl 10 lbs!!! My hams are so weak in comparison to my quads (which I curl 40 lbs)! I'm going to keep up with this routine until the pain completely goes away before returning to running.

No pain while on eliptical, but a little pain while doing standing hamstring curls on my machine...sooo...stay tuned......

**UPDATE***

I ran yesterday on my treadmill for 3.1 miles and walked an additional 5 minutes pre-workout warm-up and NO KNEE PAIN..YEAHHHHHH!!!!

It appears what I needed was to take a break (3-4 days actually). During my "break" period, I did NOT stop working out...but did non-weight bearing cardio (recumbent bike and elipticle) and I also added in weight training for about 30 min each session 3 times/week.

Thanks for all your helpful advice and tips. I've incorporated more stretching into my routine and will now run 3 times a week (never back to back days) and do non-weight bearing cardio and strength training on alternate days.

Have you tried compression tights? Or one of those knee compression bands? Unfortunately the best ones are very expensive (like CW-X or 2XU for example), but they do stabilize your knees. Also, try to avoid hills if possible, because they will really make knee problems worse.