Jacob Thomas, Ibrahim Mohamed, Babu G Vishnu, Pandian K Shyamnath Krishna, Krishnamoorthy R, Karthikeyan G, Jeyakumar P, Valarmathy V S, Hussain Jahir, Ezhilavan C S, Sridhar K, Balasubramanian Sivakumar, Varadhan S K M
Department of Applied Mechanics and Biomedical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu, 600036, India.
Department of Bioengineering, Christian Medical College, Vellore, India.
Sci Rep. 2025 May 7;15(1):15866. doi: 10.1038/s41598-025-99250-y.
Efficient manipulation of objects is crucial for daily interactions with the world. Compression neuropathies like carpal tunnel syndrome (CTS) can have detrimental effects on hand function, which can be improved by surgical intervention. Twelve patients with CTS grasped and lifted an instrumented handle while maintaining static equilibrium under different torque conditions. We compared fingertip forces and grip force variability across trials before and after surgery. Additionally, we evaluated the coordination of fingertip forces using a metric defined as synergy index to determine if there were improvements in coordination post-surgery. It was expected that there would be a decrease in fingertip forces and intertrial grip force variability indicative of recovery as well as an enhancement in synergy indices reflecting improved coordination. As expected, there was a decrease in the grip forces and intertrial variability of grip forces after surgery. However, the synergy indices were statistically similar before and after surgery, indicating that there was no change in neural strategies for coordination. Despite enhanced sensory conduction post-surgery, the central nervous system's operational strategies for motor control remained unchanged. These findings suggest that while grip force regulation improves, the underlying coordination mechanisms do not adapt in response to the surgery. The findings of this study indicate that peripheral feedback does not modulate the synergies while performing a task, suggesting that neural coordination may not change with compression neuropathies or during recovery.
高效地操纵物体对于与外界的日常互动至关重要。像腕管综合征（CTS）这样的压迫性神经病变会对手部功能产生不利影响，而手术干预可以改善这种情况。12名腕管综合征患者在不同扭矩条件下保持静态平衡时，抓握并提起一个装有仪器的手柄。我们比较了手术前后各试验中指尖力和握力的变异性。此外，我们使用定义为协同指数的指标评估指尖力的协调性，以确定手术后协调性是否有所改善。预计指尖力和试验间握力变异性会降低，这表明恢复情况良好，同时协同指数会提高，反映出协调性得到改善。正如预期的那样，手术后握力和试验间握力变异性降低。然而，手术前后的协同指数在统计学上相似，表示神经协调策略没有变化。尽管手术后感觉传导增强，但中枢神经系统用于运动控制的操作策略仍未改变。这些发现表明，虽然握力调节有所改善，但潜在的协调机制并未因手术而发生适应性变化。本研究结果表明，在执行任务时，外周反馈不会调节协同作用，这表明神经协调可能不会因压迫性神经病变或恢复过程而改变。
