My calf muscle sometimes feels tight, like its about to cramp up. I used to have a lot of muscle cramps when the BFS first started. Fewer now. Soaking in a hot tub sometimes helped. Sometimes it just goes away for no apparent reason.
I have experienced a lot of muscle tension and/or muscle cramps! For me, it seems to travel to different areas of my body. For a while it was my shoulder, then my hands, and now my left leg has been giving me a lot of pain and discomfort. I guess cramping and that type of thing can be a part of BFS, from what I've read on here! Seems that many people experience that along with the twitching!