I have the same issue with Freezing of Gait (FOG). My legs get very stiff in the middle of my walk (normally 15-20 feet) and I cant walk anymore or I fall down. I consulted my ALS doctor and he said to double up my dose of muscle relaxer Baclofen. I did that and I was fine for 3 days then it happened again.
Finally I realized it was lack of sleep that was causing my FOG. If I sleep 8-9 hours straight I am fine, if I sleep 6-7 hours I have problems. I have started to take a melatonin 12 mg. (purchased from Amazon). I have done this for 9 days now and haven’t had any issues with FOG
I am curious if anyone has tried an indoor infrared sauna to relieve muscle tightness like FOG or cramps