This is why you want to undergo a Functional Capacity Evaluation like Finz suggested previously. They test strength multiple times and after various activities, etc. Than a doc like this neuro can take the information from it and be able to answer either an RFC or this questionnaire. Otherwise, at best, they'll test your grip strength 3x's in a row, and that's about it. There is simply know way for him to know without detailed testing since patients abilities vary greatly. And based upon SS requirements, those functional capabilities can mean the difference between approval and denial.