In conjunction with force plates that helped to measure the ground reaction force ( grf ) and worked out the center of pressure ( cop ) , a motion analysis system was used to discover the 3 - d kinematic changes of the ankle , knee , hip , pelvis and trunk in the overall serving motion in the study 研究结果发现，平击和上旋发球最主要差异在于上旋发球较平击发球产生更多侧屈力矩，而此力矩的产生最主要的贡献来自于身体躯干的侧屈。
In addition , this article analyzes the structure of trunk orthosis cad system , and discusses the functions and how to realize those functions of each part according to the aspect of human body , surface modeling is used to build the three - domain trunk model ; and then through opengl technique , the model is displayed on the computer screen ; then by involving the technology of man - machine interacting , the model can be edited according to the respective body characteristics of different patients - as the improvement of man - machine interactive technology , model can be edited more freely 文中重点分析了躯干矫形器计算机辅助设计系统的组成，并对各个组成部分的功能和实现方法进行了讨论。针对人体躯干的外形特征，使用表面建模方式对躯干建立三维模型，并利用opengl技术完成模型的显示；再利用计算机实现人机交互功能，针对每位患者的形体特征对模型进行局部修改；随着人机交互技术的提高，模型修改将更加具有任意性的特点。
