Division of Kinesiology, School of Health and Human Performance, Dalhousie University, 6260 South Street, Halifax, NS, Canada B3H 4R2
Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada N2L 3G1.
J Exp Biol. 2020 Nov 18;223(Pt 22):jeb225987. doi: 10.1242/jeb.225987.
Modern human shoulder function is affected by the evolutionary adaptations that have occurred to ensure survival and prosperity of the species. Robust examination of behavioral shoulder performance and injury risk can be holistically improved through an interdisciplinary approach that integrates anthropology and biomechanics. Coordination of these fields can allow different perspectives to contribute to a more complete interpretation of biomechanics of the modern human shoulder. The purpose of this study was to develop a novel biomechanical and comparative chimpanzee glenohumeral model, designed to parallel an existing human glenohumeral model, and compare predicted musculoskeletal outputs between the two models. The chimpanzee glenohumeral model consists of three modules - an external torque module, a musculoskeletal geometric module and an internal muscle force prediction module. Together, these modules use postural kinematics, subject-specific anthropometrics, a novel shoulder rhythm, glenohumeral stability ratios, hand forces, musculoskeletal geometry and an optimization routine to estimate joint reaction forces and moments, subacromial space dimensions, and muscle and tissue forces. Using static postural data of a horizontal bimanual suspension task, predicted muscle forces and subacromial space were compared between chimpanzees and humans. Compared with chimpanzees, the human model predicted a 2 mm narrower subacromial space, deltoid muscle forces that were often double those of chimpanzees and a strong reliance on infraspinatus and teres minor (60-100% maximal force) over other rotator cuff muscles. These results agree with previous work on inter-species differences that inform basic human rotator cuff function and pathology.
现代人类的肩部功能受到进化适应的影响，这些适应确保了物种的生存和繁荣。通过整合人类学和生物力学的跨学科方法，可以全面改善行为肩部表现和受伤风险的稳健检查。这些领域的协调可以让不同的观点为更好地解释现代人类肩部的生物力学提供帮助。本研究的目的是开发一种新的生物力学和比较黑猩猩盂肱关节模型，旨在与现有的人类盂肱关节模型相平行，并比较两个模型之间预测的肌肉骨骼输出。黑猩猩盂肱关节模型由三个模块组成——外部扭矩模块、肌肉骨骼几何模块和内部肌肉力预测模块。这些模块共同使用姿势运动学、个体特定人体测量学、新的肩部节律、盂肱关节稳定性比、手部力量、肌肉骨骼几何形状和优化例程来估计关节反作用力和力矩、肩峰下空间尺寸以及肌肉和组织力。使用水平双手悬吊任务的静态姿势数据，比较了黑猩猩和人类之间的预测肌肉力量和肩峰下空间。与黑猩猩相比，人类模型预测的肩峰下空间窄 2 毫米，三角肌的力量通常是黑猩猩的两倍，并且强烈依赖于冈下肌和小圆肌（60-100%最大力）而不是其他肩袖肌肉。这些结果与关于种间差异的先前工作一致，这些工作为基本的人类肩袖功能和病理学提供了信息。
