Thank you for your question. Although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
This muscle twitching is also called as muscle fasciculation & appears when the muscle contracts on its own (without nerve stimulation). Most of the times these symptoms occur without any underlying disorder & they are not harmful or may appear after viral illness/or long term illness. But sometimes this muscle twitching appears as atrophy and weakness of muscle as well. Most likely cause of this twitching with weakness/atrophy of muscle can be when the nerve supplying to calf muscle is not functioning properly due to any neurological disorder. If you suffer continuous weakness and notice reduced strength of muscle bulk in these areas, please arrange an appointment with a neurologist right away who will evaluate the possibilities here. Hope this information proves helpful to you.
Take Care & Regards!!!
It's either some problem in your lower back is doing this, or more likely could be Restless Legs Syndrome, a neuromuscular problem of unknown origin. See, it starts in the calves, and usually it's more in one calf than the other. Also, usually you'll feel that squeezing sensation when you lay down to rest. There are medications for RLS, sometimes takes a while to get the right one to work. And in a certain percentage of RLS people, it's caused by not enough iron in the bloodstream, which some labwork would determine that. And to see if it's your lower back, especially if you feel pain there, a doc can order a CAT scan to see what kind of shape your lumbar spine is in, and they usually treat that moderately with medicine and physical therapy. Try taking a multivitamin and mineral supplement with iron in it, maybe twice a week, and see if it helps your leg symptoms; if not, then you can visit a neurologist, he'll be able to do the other tests I'm referring to.