University of Novi Sad, Faculty of Medicine, Clinical Centre of Vojvodina, Clinic for Orthopedic Surgery and Traumatology, Novi Sad, Serbia.
Tesla Science Evolution Institute, Australia.
J Biomech. 2019 Sep 20;94:165-169. doi: 10.1016/j.jbiomech.2019.07.035. Epub 2019 Aug 9.
As a low-to-moderate intensity rehabilitation exercise after hip and knee surgery, we propose a dynamical model of the legs motion through the water medium in freestyle and backstroke swimming. We formulate a general Kirchhoff-Lagrangian dynamics model of the legs-propulsion through the water in post-surgical rehabilitation swimming. We start by defining the two-leg-propulsion configuration manifold. This is composed of eight Euclidean groups of rigid motions in 3D space for each of the four leg segments. Next, we define Newton-Euler dynamics for each segment. This single segmental dynamics is further generalized into Lagrangian dynamics for the whole leg-propulsion system. Finally, the water effects are added in the form of Kirchhoff's vector cross-products. In agreement with orthopaedic recommendations for post-surgical rehabilitation, numerical simulation is performed on a simplified version of the full Kirchhoff-Lagrangian dynamics model, which we call the "robotic swimming leg" - with intentionally reduced number of (microscopic, non-sagittal) degrees-of-freedom. The purpose of this development is both qualitative, for medical and physiotherapist practitioners to study, and quantitative, for biomechanics experts to analyze and further develop.
作为髋关节和膝关节手术后中低强度的康复运动，我们提出了一种通过水介质进行自由泳和仰泳的腿部运动动力学模型。我们制定了一个通过手术后康复游泳中腿部在水中推进的广义 Kirchhoff-Lagrangian 动力学模型。我们首先定义了两腿推进配置流形。这由四个腿部片段中的每一个的八个欧几里得刚体运动组构成。接下来，我们为每个片段定义牛顿-欧拉动力学。这种单一的片段动力学进一步推广为整个腿部推进系统的拉格朗日动力学。最后，以 Kirchhoff 向量叉积的形式添加水的影响。根据手术后康复的矫形建议，对简化版的完整 Kirchhoff-Lagrangian 动力学模型（我们称之为“机器人游泳腿”）进行了数值模拟，该模型故意减少了（微观的、非矢状面的）自由度数量。这种发展既具有定性意义，可供医学和物理治疗师研究，也具有定量意义，可供生物力学专家分析和进一步开发。
