Shimawaki Satoshi, Murai Takuma, Nakabayashi Masataka, Sugimoto Hideharu
Department of Mechanical and Intelligent Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, 321-8585 Tochigi, Japan.
Department of Radiology, School of Medicine, Jichi Medical University and Hospital, 3311-1 Yakushiji, Shimotsuke, 329-0498 Tochigi, Japan.
Appl Bionics Biomech. 2019 Jan 6;2019:2839648. doi: 10.1155/2019/2839648. eCollection 2019.
Motion analysis of the thumb and the four fingers during human gripping of a cylindrical object is a prerequisite for designing motion mechanisms in electronic arm prostheses and robotic hands. Conventional measurement methods include the use of angle sensors or multiple video recording of markers. In the present study, we performed X-ray computed tomography (CT) imaging on fingers gripping cylinders of three different diameters (10, 60, and 120 mm) and constructed a bone model based on these CT images to directly measure the flexion angle of each finger joint. We then compared the results with the flexion angles of joints measured using other methods. The subjects comprised 10 Japanese men with no hand injuries or diseases. Our results showed that smaller cylinder diameters were associated with significant increases in the flexion angle of all the joints of the four fingers. When focusing on the distal interphalangeal joint (DIP), there was no significant difference between any of the fingers for each of the cylinders, except between the index and middle fingers for the 10 mm-diameter cylinder. When focusing on the 10 mm-diameter cylinder, the flexion angle of the proximal interphalangeal joint (PIP) of each finger was significantly larger than that of the DIP and metacarpophalangeal joint (MP). However, no such significant difference was noted for the 120 mm-diameter cylinder. The coupling ratio (CR), which is the ratio of the flexion angles of the DIP and PIP, was significantly smaller for the 10 mm-diameter cylinder than for the 60 mm-diameter cylinder. However, there were no significant differences in CR between any of the fingers. A comparison of our study results with those derived using other methods indicated quantitative consistency for the DIP and PIP. However, for the MP, we noted differences that may be explained by the difficulty in determining the longitudinal axis of the metacarpal using other methods.
人体抓握圆柱形物体时拇指和四指的运动分析是设计电子手臂假肢和机器人手运动机制的前提条件。传统的测量方法包括使用角度传感器或对标记进行多次视频记录。在本研究中，我们对抓握三种不同直径（10、60和120毫米）圆柱体的手指进行了X射线计算机断层扫描（CT）成像，并基于这些CT图像构建了骨骼模型，以直接测量每个手指关节的屈曲角度。然后，我们将结果与使用其他方法测量的关节屈曲角度进行了比较。受试者包括10名没有手部损伤或疾病的日本男性。我们的结果表明，较小的圆柱体直径与四指所有关节的屈曲角度显著增加有关。当关注远侧指间关节（DIP）时，除了10毫米直径圆柱体的示指和中指之间，每个圆柱体的任何手指之间均无显著差异。当关注10毫米直径圆柱体时，每个手指的近侧指间关节（PIP）屈曲角度显著大于DIP和掌指关节（MP）。然而，对于120毫米直径圆柱体，未观察到此类显著差异。DIP和PIP屈曲角度之比的耦合率（CR）在10毫米直径圆柱体中显著小于60毫米直径圆柱体。然而，任何手指之间的CR均无显著差异。将我们的研究结果与使用其他方法得出的结果进行比较表明，DIP和PIP在数量上具有一致性。然而，对于MP，我们注意到存在差异，这可能是由于使用其他方法难以确定掌骨的纵轴所致。
