Accuracy of muscle moment arms estimated from MRI-based musculoskeletal models of the lower extremity.
Accuracy of muscle moment arms estimated from MRI-based musculoskeletal models of the lower extremity.
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DOI：
10.1002/1097-0150(2000)5:2
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发表时间：
2000-01-01
期刊：
影响因子：
--
通讯作者：
Delp, S L
中科院分区：
文献类型：
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作者：
Arnold, A S;Salinas, S;Delp, S L
目的：计算软组织长度和力臂的生物力学模型广泛适用于运动异常的治疗和骨科手术的规划。本研究的目标是：(i) 开发从磁共振 (MR) 图像构建特定受试者生物力学模型的方法，(ii) 创建三个下肢尸体标本的模型，以及 (iii) 量化使用这些模型估计的肌肉肌腱长度和力臂的准确性。 材料和方法：描述各种身体姿势的内侧腘绳肌和腰肌路径的模型是根据 MR 图像开发的通过定义髋部和膝部的运动学模型以及指定模拟肌肉和底层结构之间相互作用的“包裹表面”来配置关节配置。我们构建这些模型的方法是通过比较从三个样本的模型估计的髋关节和膝关节屈曲力臂与在相同样本上通过实验确定的力臂进行评估的。由于肌肉的力臂决定了其长度随关节旋转的变化，因此这些比较还测试了模型在髋部和膝部运动范围内估计肌肉肌腱长度的准确性。结果：用模型计算的力臂误差在髋部和膝部弯曲的功能范围内平均小于 4 毫米（实验值的 10% 以内）。结论：MR 成像和基于图形的肌肉骨骼建模相结合，提供了准确且可靠的模型。估计体内肌肉肌腱长度和力臂的有效方法。
OBJECTIVE: Biomechanical models that compute the lengths and moment arms of soft tissues are broadly applicable to the treatment of movement abnormalities and the planning of orthopaedic surgical procedures. The goals of this study were to: (i) develop methods to construct subject-specific biomechanical models from magnetic resonance (MR) images, (ii) create models of three lower-extremity cadaveric specimens, and (iii) quantify the accuracy of muscle-tendon lengths and moment arms estimated using these models.MATERIALS AND METHODS: Models describing the paths of the medial hamstrings and psoas muscles for a wide range of body positions were developed from MR images in one joint configuration by defining kinematic models of the hip and knee, and by specifying "wrapping surfaces" that simulate interactions between the muscles and underlying structures. Our methods for constructing these models were evaluated by comparing hip and knee flexion moment arms estimated from models of three specimens to the moment arms determined experimentally on the same specimens. Because a muscle's moment arm determines its change in length with joint rotation, these comparisons also tested the accuracy with which the models could estimate muscle-tendon lengths over a range of hip and knee motions.RESULTS: Errors in the moment arms calculated with the models, averaged over functional ranges of hip and knee flexion, were less than 4 mm (within 10% of experimental values).CONCLUSION: The combination of MR imaging and graphics-based musculoskeletal modeling provides an accurate and efficient means of estimating muscle-tendon lengths and moment arms in vivo.