Fiber type population of anti-gravity muscles in mammals with bipedal and upright posture

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K12681
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied health science
• Research Institution: Yamaguchi University
• Principal Investigator: Miyata Hirofumi 山口大学, 大学院創成科学研究科, 教授 (90190793)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 哺乳動物 / 筋線維組成 / 直立姿勢

Outline of Final Research Achievements

We have investigated population of muscle fiber type in several mammals to demonstrate adaptation patterns of animals including human muscle. The muscle samples (Gastrocnemius, Vastus lateralis, Gluteus, Longissimus, Latissimus dorsi and Triceps brachii muscles) were collected from 24 animals including 6 primates.
The significant positive relationships between populations of type-I fibers (%) and body weights (kg) were found in Gastrocnemius Gluteus and Triceps brachii muscles, but not in the other three muscles. Although human being has higher percentage of type-I muscle fiber in these muscles, the other primates do not have higher percentage of type-I muscle fibers than average values. Two animals which frequently take upright position, Prairie dog and Suricata suricatta, had higher percentage of type I fibers in trunk muscles as well as human being. The type-I muscle fiber in trunk muscle seems to have an important role in upright position of animals.

Free Research Field

運動生理学