Humans can physically move when their muscles contract to move bones via tendons, causing articular movements. Therefore, it is essential to study muscles and tendons by regarding them as “materials” to identify their properties if we want to understand how humans move. Our laboratory aims to gain more knowledge about human motions by identifying the various properties of muscles and tendons in vivo using ultrasonic diagnostic equipment and magnetic resonance imaging (MRI) equipment. By doing so, we will aim to glean knowledge useful in terms of developing artificial muscle and prosthetic equipment.