Anapol Fred, Gray J Patrick
Department of Anthropology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA.
Am J Phys Anthropol. 2003 Sep;122(1):51-65. doi: 10.1002/ajpa.10269.
The internal organization of myofibers and connective tissues has important physiologic implications for muscle function and for naturalistic behavior. In this study of forelimb muscle morphology and primate locomotion, fiber architecture is examined in the intrinsic muscles of the shoulder (musculi deltoideus, infraspinatus, supraspinatus, subscapularis, teres major, and t. minor) and arm (m. coracobrachialis, biceps brachii, brachialis, and triceps brachii) in the semiterrestrial vervets (Chlorocebus aethiops) and arboreal red-tailed guenons (Cercopithecus ascanius). Wet weights and lengths of whole muscles, lengths of fasciculi and their associated proximal and distal tendons, and angles of pinnation were measured to estimate morphologic correlates of physiologic properties of individual muscles: force, velocity/excursion, energy expense, and relative isometric or isotonic contraction. Neither mean total-shoulder:total-arm ratios for muscle mass nor total reduced physiological cross-sectional area exhibited significant (P < 0.05) interspecific differences, thus emphasizing the importance of fine-tuning musculoskeletal analyses by the data collected here. The results generally support those previously published for quadriceps femoris and triceps surae of the hind limb in these species (Anapol and Barry [1996] Am. J. Phys. Anthropol. 99:429-447). The fiber architecture of the semiterrestrial vervets is largely suited for higher velocity while running on the ground. By contrast, the architectural configuration of red-tailed monkeys implies relatively isometric muscle contraction and passive storage of elastic strain energy for exploitation of the compliant canopy, where substrate components are situated beneath the sagittal plane of the animal. With respect to relative distribution of maximum potential force output among muscles of either shoulder or arm groups in these otherwise hind limb-dominated quadrupedal primates, statistically significant interspecific differences are best interpreted in light of braking, climbing, and, for vervets, the transition between ground and canopy. The interspecific differences shown here for the intrinsic muscles of the shoulder and arm underscore the significance of intramuscular morphology in reconciling structure and function with regard to locomotor behavior. Its analysis and interpretation lend support to consideration of "semiterrestrial" as a bona fide locomotor category uniquely different from what is practiced by dedicated arboreal and terrestrial quadrupeds that occasionally visit the habitat of one another. Data from a more committed terrestrial species would clarify this enigma.
肌纤维和结缔组织的内部组织对肌肉功能和自然行为具有重要的生理意义。在这项关于前肢肌肉形态与灵长类动物运动的研究中，我们对半地栖的绿猴（Chlorocebus aethiops）和树栖的赤尾长尾猴（Cercopithecus ascanius）肩部（三角肌、冈下肌、冈上肌、肩胛下肌、大圆肌和小圆肌）和手臂（肱二头肌、肱肌、肱三头肌和喙肱肌）的固有肌肉的纤维结构进行了检查。测量了整块肌肉的湿重和长度、肌束及其相关近端和远端肌腱的长度以及羽状角，以估计个体肌肉生理特性的形态学关联：力量、速度/行程、能量消耗以及相对等长或等张收缩。无论是肌肉质量的平均总肩部：总手臂比率，还是总折合生理横截面积，种间差异均不显著（P < 0.05），因此强调了此处收集的数据对微调肌肉骨骼分析的重要性。研究结果总体上支持了此前针对这些物种后肢的股四头肌和小腿三头肌所发表的研究结果（Anapol和Barry [1996] 《美国体质人类学期刊》99:429 - 447）。半地栖绿猴的纤维结构在很大程度上适合在地面奔跑时的较高速度。相比之下，赤尾猴的结构配置意味着相对等长的肌肉收缩以及弹性应变能的被动储存，以便利用柔顺的树冠层，树冠层的底物成分位于动物矢状面下方。关于这些以四肢后肢为主的灵长类动物肩部或手臂组肌肉之间最大潜在力量输出的相对分布，根据制动、攀爬以及对于绿猴而言的地面与树冠层之间的过渡情况，对具有统计学意义的种间差异进行最佳解释。此处展示的肩部和手臂固有肌肉的种间差异强调了肌肉内形态在使结构与运动行为功能相协调方面的重要性。其分析和解释支持将“半地栖”视为一种真正独特的运动类别，它不同于专门的树栖和地栖四足动物偶尔进入彼此栖息地时所采用的运动方式。来自更典型地栖物种的数据将阐明这一谜团。
