Existential reason of human handeness examined from tool-use during grasping tasks and task difficulty

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K06874
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45060:Applied anthropology-related
• Research Institution: Prefectural University of Kumamoto
• Principal Investigator: Aoki Tomoko 熊本県立大学, 共通教育センター, 教授 (50433412)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 利き手 / 道具 / 把握運動 / 指 / 難易度

Outline of Final Research Achievements

The motor characteristics of dominant and non-dominant hands were investigated from the three perspectives of (1) tool-use, (2) familiarity to the use of tools and (3) task difficulty. We measured the forces acting on an object using 3 axes force sensor. The positions of the object and hand were examined using 3D motion capture system. Muscle activities in the arms were also measured. Interestingly, in both right- and left-handed subjects, for the dominant hand the unfamiliar tool condition took longer than the other conditions to perform the task, while for the non-dominant hand the familiar tool condition took longer than the other conditions to perform the task. These results suggest that tool use and familiarity with tool use have a strong influence on differences in motor skills between dominant and non-dominant hands.

Free Research Field

応用人類学

Academic Significance and Societal Importance of the Research Achievements

「利き手」は人間の96％に見られる現象である。利き手は非常に身近な現象にもかかわらず、そのメカニズムはほとんど解明されていない。多くの先行研究において、利き手は非利き手よりも優れた運動能力を持つことが報告されているが、どのような運動課題において利き手と非利き手の違いが最も明確になるのかは、依然として不明である。そこで、本研究では、利き手あるいは非利き手によって、物体を把握し、移動させる課題を「道具の有無」、「使い慣れた道具とそうでない道具」、「課題の難易度」の異なる条件で行い、物体の移動に要する時間、物体や手指の位置、筋活動等を調べた。