Abstract
To show the functional differences between mono- and bi-articular muscles, we recorded EMG activties of m. deltoideus and m. tricepus bracjii caput lateralis (mono-articular) and m. triceps brachii caput longum (bi-articular) during multidirectional targeting movements of a bipedal animal (human) and four-legged animal (cat). The results revealed distinct differences between the activation patterns of mono- and bi-articular muscles in human and cat. The bi-articular muscle is the majour muscle activated during targeting movements in various directions, and show large amplitude EMG bursts with long duration and short latency. Activation of the mono-articular muscles was strongly affected by movement direction, whereas that of bi-articular muscles was not. The EMG burst characteristics in cat were bilateral, which differed from the findings in human. [J Physiol Sci. 2007;57 Suppl:S159]
