Plus (+) and Minus (-) Grades Use of a plus (+) or minus (-) addition to a manual muscle test grade is discouraged except in three instances: Fair+, Poor+, and Poor-. Scalable gradations in other instances can be described in documentation as improved or deteriorated within a given test grade (such as Grade 4) without resorting to the use of plus or minus labels. The purpose of avoiding the use of plus or minus signs is to restrict the variety of manual muscle test grades to those that are meaningful and defendable.
Hislop, Helen J et al. Daniels And Worthingham’s Muscle Testing. 1st ed. Print.