9 months ago I fell on a pill of rocks and hurt my low back my left hip and my left knee and leg .when I fell my knee buckle and I fell back on the rocks one of the rocks went right between my hips and I had MRI done and X-rays but now I have pain from left hip down my left leg .also my my knee hurts a lot and my leg is weak I can't walk with out a cane and I don't fell any thing in the back of my leg is numb and I fell a lot . My doctor done a nerve test and say I have nerve hurt and now my knee cap move to the left more then half of the cap .