人上臂屈肌和伸肌的肌纤维型分布

The Fiber Tupes Distribution in the Flexor and Extensor Muscles of Arm——An Autopsy Study

研究了人上臂屈、伸肌的肌纤维型组成。上臂屈肌的Ⅰ型纤维占50-60％,其中肱肌的Ⅰ型纤维比例显著高于其他二肌。肱三头肌的Ⅰ型纤维占40-44％,三个头之间无显著差异。人类上臂肌的特点是浅、深层之间的肌纤维型组成没有差异,两型肌纤维近乎均等的比例和棋盘格式布局,说明人类上肢肌适于作快慢两种速度紧密镶嵌的、精细准确的技巧性运动。

The composition of type Ⅰ and type Ⅱ fiber in the flexor and extensor muscles of arm is investigated in autopsy. The type fibers comprises 50～60％ of the total fibers counted in the three flexors. A significantly higher proportion of type Ⅰ fiber is seen in the brachialis. The triceps brachii possesses 40～440％ of type Ⅰ fiber,no difference is found among its three heads. The human arm muscles are characterized by their lack of differenciation in fiber types composition between superficial and deeper portion, and as a whole, their nearly epual distribution of two fiber types in a muscle arranged in a mosaic pattern. It seems to the authors that evidences support the suggestion that the human arm muscles in comparison to other mammals are especially adaptable to technical manufactures in a delicate manner with closely related transfer of fast and slow velocities.