Arauz Paul G, Sisto Sue A, Kao Imin
J Biomech Eng. 2016 May;138(5):051005. doi: 10.1115/1.4032967.
This article presented an assessment of quantitative measures of workspace (WS) attributes under simulated proximal interphalangeal (PIP) joint arthrodesis of the index finger. Seven healthy subjects were tested with the PIP joint unconstrained (UC) and constrained to selected angles using a motion analysis system. A model of the constrained finger was developed in order to address the impact of the inclusion of prescribed joint arthrodesis angles on WS attributes. Model parameters were obtained from system identification experiments involving flexion-extension (FE) movements of the UC and constrained finger. The data of experimental FE movements of the constrained finger were used to generate the two-dimensional (2D) WS boundaries and to validate the model. A weighted criterion was formulated to define an optimal constraint angle among several system parameters. Results indicated that a PIP joint immobilization angle of 40-50 deg of flexion maximized the 2D WS. The analysis of the aspect ratio of the 2D WS indicated that the WS was more evenly distributed as the imposed PIP joint constraint angle increased. With the imposed PIP joint constraint angles of 30 deg, 40 deg, 50 deg, and 60 deg of flexion, the normalized maximum distance of fingertip reach was reduced by approximately 3%, 4%, 7%, and 9%, respectively.
本文介绍了在模拟食指近端指间关节（PIP）融合情况下对工作空间（WS）属性定量测量的评估。使用运动分析系统对7名健康受试者进行测试，测试时PIP关节无约束（UC）以及将其约束到选定角度。为了研究纳入规定关节融合角度对WS属性的影响，建立了一个受约束手指的模型。模型参数通过涉及UC手指和受约束手指屈伸（FE）运动的系统识别实验获得。受约束手指的实验FE运动数据用于生成二维（2D）WS边界并验证模型。制定了一个加权标准来定义几个系统参数中的最佳约束角度。结果表明，PIP关节固定在40 - 50度屈曲角度时，2D WS达到最大值。对2D WS长宽比的分析表明，随着施加的PIP关节约束角度增加，WS分布更加均匀。当施加的PIP关节约束角度为30度、40度、50度和60度屈曲时，指尖到达的归一化最大距离分别减少了约3%、4%、7%和9%。
