Raison Maxime, Aubin Carl-Eric, Detrembleur Christine, Fisette Paul, Mahaudens Philippe, Samin Jean-Claude
Université catholique de Louvain, Centre for Research in Mechatronics, Louvain-la-Neuve, Belgium.
Stud Health Technol Inform. 2010;158:107-11.
The internal forces in the human body in motion could provide valuable information for the evaluation and follow-up of subjects with musculo-skeletal pathologies, such as scoliosis, but are still difficult to accurately measure. In this context, the objective of this study is to quantify the global intervertebral torques along the spine during walking, in order to compare the dynamical behavior between two subjects with different scoliosis severities. Practically, two patients, both with left lumbar adolescent idiopathic scoliosis (lumbar Cobb angles: 40 degrees), but with different apical axial rotations (20 degrees and 30 degrees) and different thoracic Cobb angles (20 degrees and 30 degrees), walked on a treadmill at 4 km/h. The acquisition system included optokinetic sensors (reflective markers), recording the 3D-joint coordinates, and a treadmill equipped with strain gauges, measuring the external forces independently applied to both feet. The global intervertebral torques were computed using an inverse dynamic model of the human body in 3D. As results, significant differences of the subject kinematics and ground reaction forces were recorded, which lead to different internal torque behavior in magnitude, maxima and minima when normalized to the subject mass. In conclusion in this preliminary study, different dynamical behavior was found between two subjects with different scoliosis severities, suggesting that the scoliosis severity could be affected by abnormal internal torques along the spine during gait (different than in the standing posture), which could lead to a supplementary asymmetric growth modulation of the vertebrae and the further progression of the scoliotic deformities in the framework of the Hueter-Volkman principle. Finally, this is a pilot study and the results will inform future studies and biomechanical modeling.
人体运动时的内力可为评估和跟踪肌肉骨骼疾病患者（如脊柱侧弯患者）提供有价值的信息，但仍难以精确测量。在此背景下，本研究的目的是量化步行过程中脊柱整体的椎间扭矩，以便比较两名脊柱侧弯严重程度不同的受试者的动态行为。实际上，两名患有左侧腰椎青少年特发性脊柱侧弯（腰椎Cobb角：40度）但顶椎轴向旋转角度不同（20度和30度）以及胸椎Cobb角不同（20度和30度）的患者，以4公里/小时的速度在跑步机上行走。采集系统包括视动传感器（反光标记），用于记录三维关节坐标，以及一台配备应变片的跑步机，用于独立测量施加在双脚上的外力。使用人体三维逆动力学模型计算整体椎间扭矩。结果显示，记录到受试者运动学和地面反作用力存在显著差异，当按受试者体重进行归一化处理时，这些差异导致了内部扭矩行为在大小、最大值和最小值方面的不同。总之，在这项初步研究中，发现两名脊柱侧弯严重程度不同的受试者之间存在不同的动态行为，这表明脊柱侧弯的严重程度可能受到步态期间脊柱异常内部扭矩的影响（与站立姿势不同），这可能导致椎体的补充性不对称生长调节以及脊柱侧弯畸形在胡特 - 沃尔克曼原理框架下的进一步发展。最后，这是一项初步研究，其结果将为未来的研究和生物力学建模提供参考。
