Functional Evaluation of Effective Leg Muscular Strength Based on a Muscle Coordinate System Composed of Bi-articular and Mono-articular Muscles. Estimation of Functional Effective Muscular Strength from Output Force Distribution.

Abstract

It has been reported that, in the two joint motor link system of the human arm, complicate muscular alignments were simplified into three antagonistic pairs of six muscles including mono- and bi-articular muscles and these six muscle strengths were defined as functionally effective muscular strengths (FEMS), and the output force distribution exerted at the endpoint of the two-joint link system comes hexagonal shape, and further the six FEMS could be estimated based on the hexagonal characteristics of the output force distribution. In this study, it has been revealed that the same relationship between the output force distribution and the FEMS could be seen in the human leg as seen in the human arm, and the leg FEMS could be estimated with the ratio between the physiological cross sectional arias (PCSA) of the antagonistic biarticular leg muscles, because of its very little variation among the previous reports.