Davis J R, Mirka G A
Department of Industrial Engineering, North Carolina State University, Raleigh, USA.
Spine (Phila Pa 1976). 2000 Jan 15;25(2):180-9. doi: 10.1097/00007632-200001150-00007.
An electromyography-assisted biomechanical model was developed using electromyographic (surface and in-dwelling) data collected during asymmetric lifting and twisting activities.
To develop a biomechanical model of the lumbar region that considers the ability of the broad, flat muscles of the trunk (external obliques, internal obliques and latissimus dorsi) to activate different anatomic regions at different intensity levels and then uses this information to describe the spine reaction forces that result during lifting and twisting tasks.
Many biomechanical models of the lumbar region use single-vector representations for the external oblique, internal oblique, and latissimus dorsi muscles. This simplification limits the description of the complexity of the resultant forces produced by these muscles and does not consider their differential activation capacity.
Human subjects performed lifting and twisting exertions while muscle electromyographic activities were sampled at one location on the rectus abdominis and erector spinae muscles and at multiple locations on the latissimus dorsi, external oblique, and internal oblique muscles. These data were used in conjunction with in vivo digitized muscle origin and insertion points to predict muscle forces and spine loads through the use of the electromyography-assisted modeling method.
The measures of model performance such as percentage of error (6-21%) in the prediction of the external torques, correlations (0.83-0.98) between internal and external torques and the values of predicted muscle force capacity were all similar to data collected in previous electromyography-assisted models, but the predictions of spinal loading, particularly shear forces, were quite different. The results have shown that by modeling the broad, flat muscles of the torso using multiple-force vectors, the calculated shear forces in the spine were reduced.
The multivector, transverse-contour model developed in this research illustrates the importance of realistic multiple-vector modeling and the importance of considering the selective-activation capacity of the abdominal oblique musculature.
利用不对称提举和扭转活动期间收集的肌电图（表面和植入式）数据，开发了一种肌电图辅助生物力学模型。
建立一个腰椎生物力学模型，该模型考虑躯干宽阔扁平肌肉（腹外斜肌、腹内斜肌和背阔肌）在不同强度水平激活不同解剖区域的能力，然后利用这些信息描述提举和扭转任务期间产生的脊柱反作用力。
许多腰椎生物力学模型对外斜肌、内斜肌和背阔肌采用单向量表示。这种简化限制了对这些肌肉产生的合力复杂性的描述，且未考虑它们的差异激活能力。
人类受试者进行提举和扭转用力动作，同时在腹直肌和竖脊肌的一个位置以及背阔肌、腹外斜肌和腹内斜肌的多个位置采集肌肉肌电图活动数据。这些数据与体内数字化的肌肉起止点数据相结合，通过肌电图辅助建模方法预测肌肉力量和脊柱负荷。
模型性能指标，如外部扭矩预测中的误差百分比（6 - 21%）、内部和外部扭矩之间的相关性（0.83 - 0.98）以及预测的肌肉力量容量值，均与先前肌电图辅助模型收集的数据相似，但脊柱负荷的预测，尤其是剪切力，有很大不同。结果表明，通过使用多力向量对躯干宽阔扁平肌肉进行建模，脊柱中计算出的剪切力降低。
本研究中开发的多向量横向轮廓模型说明了逼真的多向量建模的重要性以及考虑腹斜肌选择性激活能力的重要性。
