Brown Nicholas A T, Pandy Marcus G, Kawcak Christopher E, McIlwraith C Wayne
Department of Biomedical Engineering, The University of Texas, Austin, USA.
J Anat. 2003 Jul;203(1):101-13. doi: 10.1046/j.1469-7580.2003.00206.x.
A detailed musculoskeletal model of the distal equine forelimb was developed to study the influence of musculoskeletal geometry (i.e. muscle paths) and muscle physiology (i.e. force-length properties) on the force- and moment-generating capacities of muscles crossing the carpal and metacarpophalangeal joints. The distal forelimb skeleton was represented as a five degree-of-freedom kinematic linkage comprised of eight bones (humerus, radius and ulna combined, proximal carpus, distal carpus, metacarpus, proximal phalanx, intermediate phalanx and distal phalanx) and seven joints (elbow, radiocarpal, intercarpal, carpometacarpal, metacarpophalangeal (MCP), proximal interphalangeal (pastern) and distal interphalangeal (coffin)). Bone surfaces were reconstructed from computed tomography scans obtained from the left forelimb of a Thoroughbred horse. The model was actuated by nine muscle-tendon units. Each unit was represented as a three-element Hill-type muscle in series with an elastic tendon. Architectural parameters specifying the force-producing properties of each muscle-tendon unit were found by dissecting seven forelimbs from five Thoroughbred horses. Maximum isometric moments were calculated for a wide range of joint angles by fully activating the extensor and flexor muscles crossing the carpus and MCP joint. Peak isometric moments generated by the flexor muscles were an order of magnitude greater than those generated by the extensor muscles at both the carpus and the MCP joint. For each flexor muscle in the model, the shape of the maximum isometric joint moment-angle curve was dominated by the variation in muscle force. By contrast, the moment-angle curves for the muscles that extend the MCP joint were determined mainly by the variation in muscle moment arms. The suspensory and check ligaments contributed more than half of the total support moment developed about the MCP joint in the model. When combined with appropriate in vivo measurements of joint kinematics and ground-reaction forces, the model may be used to determine muscle-tendon and joint-reaction forces generated during gait.
构建了一个详细的马前肢远端肌肉骨骼模型，以研究肌肉骨骼几何结构（即肌肉路径）和肌肉生理学（即力-长度特性）对跨越腕关节和掌指关节的肌肉产生力和力矩能力的影响。前肢远端骨骼被表示为一个由八块骨头（肱骨、桡骨和尺骨合并、近端腕骨、远端腕骨、掌骨、近端指骨、中间指骨和远端指骨）和七个关节（肘关节、桡腕关节、腕间关节、腕掌关节、掌指关节（MCP）、近端指间关节（系关节）和远端指间关节（蹄关节））组成的五自由度运动链。骨表面是根据从一匹纯种马的左前肢获得的计算机断层扫描重建的。该模型由九个肌腱单元驱动。每个单元被表示为一个与弹性肌腱串联的三元件希尔型肌肉。通过解剖来自五匹纯种马的七个前肢，确定了指定每个肌腱单元产生力特性的结构参数。通过完全激活跨越腕关节和MCP关节的伸肌和屈肌，计算了广泛关节角度范围内的最大等长力矩。在腕关节和MCP关节处，屈肌产生的峰值等长力矩比伸肌产生的力矩大一个数量级。对于模型中的每块屈肌，最大等长关节力矩-角度曲线的形状主要由肌肉力的变化决定。相比之下，伸展MCP关节的肌肉的力矩-角度曲线主要由肌肉力臂的变化决定。在模型中，悬韧带和支韧带对围绕MCP关节产生的总支撑力矩的贡献超过一半。当与关节运动学和地面反作用力的适当体内测量相结合时，该模型可用于确定步态期间产生的肌腱和关节反作用力。
