I experiance these pains as well in my legs normally when trying to so I would say yes it is related to MS. I have found the CBD in medical marijuana is the only thing that gets it to go away for me. I would tell your neurologist about this new symptom.

Could be sciatica pain. I have similar pain when my back goes out

I get those also. My legs will start to tremble to where I have issues walking. It will last anywhere from just a day or so to a month. I would check with your MD and let him/her know what new issues you're having. I've been on Avonex for many years but was recently taken off and put on Teciferda. Other not having to give myself shots and taking pills everyday I haven't really noticed any changes

Could be a spastic cramp and they are often associated with MS. I take 400 MG of magnesium daily (neuro approved) and it brought most of that to a complete halt.