Abstract
[Purpose] This study was designed to clarify the relationship between grade 3 muscle strength (moment Mfair: Mf) and the maximum muscle strength (moment Mmax: Mm) in manual muscle testing. [Subjects] The subjects were 35 right dominant arms of 35 healthy persons (mean age: 21.2 years). [Methods] Tasks performed in the experiment included maximal force isometric muscle contraction in each motion of shoulder flexion, scaption, abduction, and elbow flexion. The maximum resistance in each experimental task was determined with a hand-held dynamometer. Mf and Mm were calculated to test for no correlation, regression analysis, and to test parallelism in analysis of covariance. [Results] There was a highly positive correlation between Mf and Mm in all of the experimental tasks. We confirmed that all of the 4 regression lines could be used to predict Mm, whereas parallelism of the 4 regression lines was rejected. [Conclusion] There was a linear correlation between Mf and Mm, but the results indicate that the correlation was different for each motion.
