I started with....
Foot drop. More than a decade before I was diagnosed with Primary Progressive MS, I experienced weakness in my right foot that caused it to drop whenever I walked for any distance. It quickly advanced to where my toes would "grab" on carpet or pavement and I'd crash to the ground. I eventually learned how to fall safely (?), but foot drop was the precursor for what was yet to come.
Sounds awful. I've got the beginnings of this symptom and am doing more physio on my left foot for this reason.
I was first diagnosed as primary but it's now gone to secondary. I was struggling with foot drop on my right leg and had physio. He referred me to the Prosthetics department and I've got a device now, a bit like a brace. It's light weight and attaches to my shoe and has a velcro strap around my leg. It really helped at first especially with driving. There are also device called FES - an electric pulse to make the muscle work I believe. Ask your GP or MS nurse for a referral.