I have similar issues with severe and moderate foraminal stenosis at the L4/L5 level with genetically fused L5 to S1. The twitching is most definitely causing it. I get tingling, twitching, buzzing and pins and needles. Both legs some days are ok and it can jump around. Normal EMG but a disc collapse, stenosis and DDD. I was also described as having BFS in addition to the sensations coming out of the L4/L5/S1 nerve root. The calf issues was the first thing I notice about 5-6 years ago. Probably was there longer. I did a epidural and it helped a lot - some P/T exercises rode a bike and did circuit training. The past couple of years it has not bothered me so I started pushing a little harder and now it’s back again with a vengeance. I have a consult with the ortho and will likely get scanned again to see if it’s worse or just a flare up. I had found these videos which might help you.