评估有无负荷及不同步态下踝关节受力的简化动力学模型

A Simple Dynamic Model for Assessing the Forces on Ankle Joint under Different Loads and Different Gaits

为了评价不同情况下的踝关节受力,以满足下肢保护器具以及鞋类的研发需求,建立了一个简化的下肢动力学模型:用二维刚性杆模型模拟下肢,踝关节和髋关节被简化为铰链连接,肌肉作用力分别由小腿两端的未知作用力表示,并根据测得的身体各部分重力和足底压力,利用力矩平衡方程来确定关节力矩。针对该模型建立了相应的动力学方程,结合高速摄像机和力平台获得的数据,并使用动作分析系统(APAS)对数据进行动态处理,便捷地得到了较高精度的踝关节受力数据。利用该动力学模型可以评估踝关节的受力情况,评价不同步态(如行走、跑步和踏步等)以及有、无负重时踝关节受力的差别,还可对穿着不同鞋类(跑鞋、登山鞋)和裸足时的踝关节受力进行对比分析。此项研究可应用于下肢保护器具、临床康复器具和鞋类的研发中对踝关节受力的评价。

To evaluate the forces on the ankle joint in different situations so as to meet the development requirements of lower limb protection appliances and footwear,a simple lower limb dynamic model is established.The lower limb is simulated by the two-dimensional rigid rod model,in which the ankle joint and the hip joint are simplified as hinge connections,and the muscle forces are expressed by unknown forces at both ends of the calf.Using the measured plantar pressure,the joint torque is determined based on the equilibrium equation of torques.For the dynamic model,the corresponding kinetic equation is derived.Accurate ankle joint force data are obtained through high-speed photography and force platform,and the dynamic data is processed by the action analysis system（APAS）.The kinetic model can be used to assess the forces on the ankle joint,and evaluate the force difference among different gaits（such as walking,running and stepping）and between the conditions with and without load.Moreover,the model can be applied to force analysis of ankle joint with wearing different footwear（e.g.running shoes and hiking shoes）or bare feet,and is expected to be applicable to the evaluation of ankle joint force in development of clinical rehabilitation apparatus,lower limb protection appliances,and footwear.