Lee Hangil, Park Jeong-Ho, Shin Joon-Ho, Roh Jinsook, Park Hyung-Soon
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea.
Department of Neurorehabilitation, National Rehabilitation Center, Seoul, 01022, South Korea.
J Neuroeng Rehabil. 2025 Apr 28;22(1):99. doi: 10.1186/s12984-025-01630-y.
Effective motor task execution relies on precise muscle coordination, which is often disrupted after a stroke, leading to impaired motor functions. Post-stroke, alterations in intermuscular coordination, including abnormal coupling of shoulder abductor muscles, are commonly observed and contribute to these impairments. Traditional rehabilitation often overlooks this complex intermuscular coordination, and there is a need for intuitive strategies to modify abnormal muscle synergies.
This study introduced a novel "muscle-to-action mapping" approach to alter activation profiles of stroke affected muscle synergies. Muscle-to-action mapping trains complex muscle synergies by mapping them to intuitive motions or force directions. By mimicking target actions, patients can achieve desired muscle activation patterns. The feasibility of this approach for correcting abnormal intermuscular coordination and improving force control during reaching was tested in stroke survivors.
A force tracking training system using muscle-to-action mapping was developed to modify abnormal synergy activation profiles during isokinetic reaching tasks. The system guided muscle activation by predicting the direction of endpoint force needed to activate specific muscle synergies, deviating from habitual patterns. The system's effectiveness was evaluated in eleven chronic stroke survivors, measuring changes in muscle synergies, endpoint force control, and clinical assessment scores.
The intervention significantly enhanced targeted muscle synergy activations and endpoint force control, demonstrating the training's ability to induce desired muscle synergy activation profiles through muscle-to-action mapping. The overall structure of muscle synergies remained mostly unchanged post-training, highlighting the potential to modify activation profiles without altering synergy vectors. Functional improvements were reflected in the Fugl-Meyer Assessment for the Upper Extremity and Wolf Motor Function Test scores, which increased by 3.36 and 6.45 points, respectively.
This study validates muscle-to-action mapping for training muscle synergy activation profiles in stroke survivors. Using a biomechanical model to generate endpoint forces, this method effectively altered synergy activation profiles and improved force control during reaching tasks, leading to clinical improvements. These findings indicate that muscle-to-action mapping could be a valuable addition to stroke rehabilitation, offering an intuitive method for enhancing intermuscular coordination and motor recovery.
Registered in Clinical Research Information System of Korea National Institute of Health (KCT0005803).
有效的运动任务执行依赖于精确的肌肉协调，而中风后这种协调常常被破坏，导致运动功能受损。中风后，常见肌肉间协调的改变，包括肩外展肌的异常耦合，这也是导致这些损伤的原因之一。传统康复往往忽略了这种复杂的肌肉间协调，因此需要直观的策略来改变异常的肌肉协同作用。
本研究引入了一种新颖的“肌肉到动作映射”方法来改变中风患者受影响肌肉协同作用的激活模式。肌肉到动作映射通过将复杂的肌肉协同作用映射到直观的动作或力的方向来训练它们。通过模仿目标动作，患者可以实现所需的肌肉激活模式。本研究在中风幸存者中测试了这种方法纠正异常肌肉间协调和改善伸手过程中力控制的可行性。
开发了一种使用肌肉到动作映射的力跟踪训练系统，以在等速伸手任务中改变异常的协同激活模式。该系统通过预测激活特定肌肉协同作用所需的端点力方向来引导肌肉激活，偏离习惯模式。在11名慢性中风幸存者中评估了该系统的有效性，测量了肌肉协同作用、端点力控制和临床评估分数的变化。
干预显著增强了目标肌肉协同作用的激活和端点力控制，证明了该训练通过肌肉到动作映射诱导所需肌肉协同作用激活模式的能力。训练后肌肉协同作用的整体结构大多保持不变，突出了在不改变协同向量的情况下改变激活模式的潜力。功能改善反映在上肢Fugl-Meyer评估和Wolf运动功能测试分数上，分别提高了3.36分和6.45分。
本研究验证了肌肉到动作映射在中风幸存者中训练肌肉协同作用激活模式的有效性。该方法使用生物力学模型生成端点力，有效地改变了协同激活模式，并改善了伸手任务中的力控制，从而带来了临床改善。这些发现表明，肌肉到动作映射可能是中风康复的一个有价值的补充，为增强肌肉间协调和运动恢复提供了一种直观的方法。
在韩国国立卫生研究院临床研究信息系统注册（KCT0005803）。
