A couple of years ago I was diagnosed with lumbar radiculopathy,neruitis sciatic, and have 2 bulging discs in my lower back. I started treatment for the low back pain with ESI (Epidural Steroid Injections). Mar 2012 I received a fourth injection. The next day my left knee started buckling while I was walking. By the second day, both my legs had given out and I couldn't walk unassisted. I could stll feel them but when I attempted to walk they both would crumple to the ground. Almost a year later, several tests, and physical therapy the doctors are unable to determine the cause. My right leg appears to be fine and I can bear weight on it but my left leg is the opposite. Each time I walk my left knee gves out. I am still unable to weight bear on my left leg. Any thoughts?