Functional Morphology of Primate Epaxial Muscles.

由于外轴肌结构复杂，其功能与形态之间的关系研究较少。然而，为了获得直立的两足习惯，需要对外轴结构的形态和功能进行修改。因此，对包括人类在内的灵长类动物外轴肌的功能形态学研究将是一个重要的研究课题。我们计划通过大体解剖、组织学和肌电分析三个方面来研究这个问题。我们选择陆生的僧帽猴和僧帽狒狒作为大体解剖研究的材料，是因为首席研究员已经积累了灵长类动物的树栖物种。结果表明，陆生物种胸腰椎连接处的外轴肌结构比陆生物种大。我们试图鉴定更多的肌纺锤体成员在颈外轴肌。因为肌肉蜘蛛的相对数量反映了反馈信息的多少，所以蜘蛛数量多的肌肉充当关节运动的传感器。在此基础上，对肌电活动不易检测的深层肌的功能进行研究。对5种灵长类动物的实验结果表明，肌纺锤体的相对数量存在种间差异。此外，这种变异可能与物种特有的运动模式有关。研究了日本猕猴体位和运动行为时腰竖脊肌的肌肉活动。虽然该肌肉在坐着或水平四足行走时不活跃，但在两足站立和两足行走时观察到双侧维持活动。这些双侧活动将延伸到猕猴的胸腰椎连接处，并维持这些姿势和运动。少

The correlation between finction and morphology of the epaxial muscle were not enough investigated, because of its complex structure. However, the demand for the modification of the morphology and function in the epaxial structure would be needed to acquisit human erect bipedal habit. Thus the functional-morphological studies of the epaxial muscle of the primate, which includes human, would be the important research problem.We planned to study this problem by means of the three aspects which inluded the gross anatomical study, histological study and EMG analysis.We selected the terrestrial patas monkey and hamadryas baboon as the materials for the gross anatomical study, because head investigator have already accumulated arboreal species of the primates. The comparison between arboreal and terrestrial species revealed that the epaxial muscle structure in the thoraco-lumbar junction of the terrestrial species was more massive than those of arboreal species.We attempted to qualify the nu … More mber of the muscle spindles in the cervical epaxial muscles. Because the relative number of the muscle spidles would reflect the amount of the feed-back information, the muscle which have large number of spidles would act the sensor of the joint motion. After this correlation, the function of the deep muscle, whose EMG activity can not be tested easily, would be investigated.The results from the five species of the primates suggested that the interspecific variation existed in the relative number of the muscle spindle. Furthermore, this variation might correlated to the species-specific mode of locmotion.The muscular activity of the lumber erector spinae muscle of the Japanese macaque were investigated during postural and locomotor behavior. Although this muscle were not active during sitting or level quadrupedal walking, the bilateral sustaining activities were observed in bipedal standing and bipedal walking. These bilateral activity would extend to the thoraco-lumbar junction of the macaque and maintain these posture and locmotion. Less