Sure it can. Sensation is a subjective measure by the patient themselves. If the patient takes a drug then you ask if sensation improves, they could certainly say "it feels like it's improving".
And with regards to ability to walk, fatigue is often a major complaint in MS. If the patient takes a drug, "feels better", they may have more energy and do better on a walk test.
There are measure where a placebo effect is unlikely, such as blood tests of biomarkers or physical processes that are easily measurable without having to ask the patient (e.g. plaque buildup on arterial walls).
I think you're vastly and grossly underestimating how multiple sclerosis impacts your nervous system if you think that a placebo effect making you "feel better" will give you the ability to walk again.
It's actually a little stunning, reading your position on this.
It's not my position, it's the FDA's position. Take a look at some of the FDA's comments on other disabling diseases like Duchenne's muscular dystrophy. An improve in an ability to walk (6 minute walk test, 6MWT) is view with skepticism by clinicians.
And with regards to ability to walk, fatigue is often a major complaint in MS. If the patient takes a drug, "feels better", they may have more energy and do better on a walk test.
There are measure where a placebo effect is unlikely, such as blood tests of biomarkers or physical processes that are easily measurable without having to ask the patient (e.g. plaque buildup on arterial walls).