Development of Teaching Materials to Examine the Relationship Between the Structure and Function of Bones and Muscles: Arm Models

Abstract

In the learning unit, “the structure and function of the human body” of natural science in the fourth grade of Japanese elementary school, various teaching materials, including models of the human arm, are available on the market, and many models constructed by teachers and researchers are also available. However, some of these models have problems regarding the reproducibility of bones, joints, and muscles. In addition, there are many cases of muscle contraction due to the bending of the elbow joint, which is contrary to the actual causal relationship and therefore confusing for students. Finally, some of the available materials are inflexible in that they do not adequately reflect children’s ingenuity and independent activities. Therefore, the authors set out to develop teaching material models that eliminate the above-mentioned problems and propose a lesson plan that utilizes these new models. In the new models, the arm bones are represented by three pieces of square-section timber, and the elbow joint is designed to recreate the mechanism of the hinge joint by devising a method of how to connect the three pieces of wood. Using a toy “Miracle Rocket” for the muscles, we were able to express how the muscles contracted and expanded, and how they relaxed and returned to their original length. These devices cause the children to think about the positions of tendons and encourages them to clarify the causal relationship in which the arm moves due to the contraction of muscles. By using these materials, schoolchildren will be able to actively work on solving problems in pairs and in groups throughout the learning unit.