What distinguishes MMT grade 1 from grade 0?

• A. Grade 1 shows identifiable muscle contraction with effort; Grade 0 shows no contraction felt or seen
• B. Grade 1 shows full ROM; Grade 0 shows no ROM
• C. Grade 1 shows movement against gravity; Grade 0 shows no movement
• D. Grade 1 shows no contraction felt; Grade 0 shows contraction

Answer: (A)

In manual muscle testing, the key distinction between the first level and the zero level is whether any muscle activation can be detected. The first level reflects a trace contraction—you can palpate or observe a tiny, identifiable contraction of the muscle, even though it’s not enough to move the joint. If there’s no contraction that can be felt or seen at all, that’s the zero level. This is why the first level indicates some neural activation without movement, while the zero level indicates no detectable muscle activation. The other statements don’t fit because movement or ROM isn’t present at this minimal activation level, and stating no contraction is present would be incorrect for the first level.