Li Zong-Ming, Davis Gregg, Gustafson Norm P, Goitz Robert J
Hand Research Laboratory, Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
J Orthop Res. 2006 Mar;24(3):407-15. doi: 10.1002/jor.20046.
The tightness of intrinsic hand muscles is a common cause of finger joint stiffness. The purposes of this study were to develop a robot-assisted methodology to obtain torque-angle data of a finger joint, and to investigate the regulation of the intrinsic muscles on finger joint stiffness. Our robot system features the integration of a low payload robot arm, a controller, and a force/torque transducer. The system provided highly reproducible torque-angle curves. Torque-angle data of the proximal interphalangeal joint with the metacarpophalangeal joint at 0 and 60 degrees were obtained from eight asymptomatic hands. The torque-angle curve shifted with the position of the metacarpophalangeal joint. As the metacarpophalangeal joint flexion angle changed from 60 to 0 degrees, the equilibrium of the proximal interphalangeal joint increased more than 20 degrees, and joint stiffness increased more than 50%. The dependence of the stiffness of the proximal interphalangeal joint on metacarpophalangeal joint position supports the regulatory role of the intrinsic muscles on finger joint mechanics. This regulatory mechanics is likely amplified in hands with intrinsic muscle tightness, justifying the commonly used Bunnell Intrinsic Tightness Test.
手部固有肌的紧张是手指关节僵硬的常见原因。本研究的目的是开发一种机器人辅助方法来获取手指关节的扭矩-角度数据，并研究固有肌对手指关节僵硬的调节作用。我们的机器人系统的特点是集成了一个低负载机器人手臂、一个控制器和一个力/扭矩传感器。该系统提供了高度可重复的扭矩-角度曲线。从八只无症状的手上获取了掌指关节处于0度和60度时近端指间关节的扭矩-角度数据。扭矩-角度曲线随掌指关节的位置而变化。当掌指关节屈曲角度从60度变为0度时，近端指间关节的平衡点增加超过20度，关节僵硬增加超过50%。近端指间关节僵硬对掌指关节位置的依赖性支持了固有肌在手指关节力学中的调节作用。这种调节力学在固有肌紧张的手中可能会被放大，这证明了常用的邦内尔固有肌紧张试验的合理性。
