The object of this study is to examine the validity of the “Principle of Minimal Total Muscular Force” proposed by MacConaill. Evidence of this minimal theory is based largely on the experimental results of Basmajian and Latif on elbow flexion. Based on physiological and physical considerations, mathematical models of the movement and maintenance of elbow flexion are constructed. Theoretical studies are made on the proposed mathematical models using minimal total muscular force as the optimization criterion. Theoretical results contradict the experimental results of Basmajian and Latif. The analysis shows that the “Principle of Minimal Total Muscular Force” is unlikely to be true.