Cusack William F, Patterson Rebecca, Thach Scott, Kistenberg Robert S, Wheaton Lewis A
School of Applied Physiology, Georgia Institute of Technology, 555 14th Street NW, Atlanta, GA, 30318, USA.
Exp Brain Res. 2014 Jul;232(7):2143-54. doi: 10.1007/s00221-014-3904-2. Epub 2014 Mar 19.
Our previous work demonstrated that the action encoding parietofrontal network, which is crucial in planning and executing motor tasks, is less active in prosthesis users who imitate movements of intact actors (mismatched limb) versus prosthesis users (matched limb). Such activation could have behavioral consequences in prosthesis users rehabilitating with intact therapists. The goal was to identify behavioral effects of matched versus mismatched limb action imitation in naïve users of prostheses. Intact subjects donned a specially adapted prosthetic device to simulate the wrist and forearm movement that transradial amputees experience. While electrogoniometry was recorded, non-amputated prosthesis users (NAPUs) observed and imitated demonstrations of a skillful motor task performed by either an intact actor or NAPU. We hypothesized that NAPUs would elicit less motion variability when performing matched versus mismatched imitation. Matched imitation resulted in a significant decrease in shoulder motion variability compared with mismatched imitation. The matched group also developed elbow motion patterns similar to the NAPU demonstrator, while the mismatched group attempted patterns similar to the intact demonstrator. This suggests a behavioral advantage to matched imitation when adapting to a prosthetic device, as it yielded more consistent movements and facilitated development of new motor patterns. Further, these results suggest that when prosthesis users are faced with the impossible task of imitating movements of an intact hand, they perform this action with greater variability and poorer technique. This work has implications on how prosthetic device operation is conveyed to persons with amputation as their clinical interactions often involve mismatched limb imitation.
我们之前的研究表明，在计划和执行运动任务中起关键作用的动作编码顶叶额叶网络，在模仿健全演员动作（肢体不匹配）的假肢使用者与假肢使用者（肢体匹配）相比时，活跃度较低。这种激活可能会对与健全治疗师一起康复的假肢使用者产生行为后果。目标是确定在初次使用假肢的用户中，肢体匹配与不匹配动作模仿的行为影响。健全受试者佩戴一种经过特殊改装的假肢装置，以模拟经桡骨截肢者所经历的手腕和前臂运动。在记录角度测量时，未截肢的假肢使用者（NAPU）观察并模仿由健全演员或NAPU执行的熟练运动任务演示。我们假设，与不匹配模仿相比，NAPU在进行匹配模仿时会产生较小的运动变异性。与不匹配模仿相比，匹配模仿导致肩部运动变异性显著降低。匹配组还形成了与NAPU演示者相似的肘部运动模式，而不匹配组则尝试与健全演示者相似的模式。这表明在适应假肢装置时，匹配模仿具有行为优势，因为它产生了更一致的运动并促进了新运动模式的发展。此外，这些结果表明，当假肢使用者面临模仿健全手动作的不可能完成的任务时，他们执行该动作时的变异性更大且技术更差。这项工作对如何向截肢者传达假肢装置操作具有启示意义，因为他们的临床互动通常涉及肢体不匹配的模仿。
