跑步着地时重复的被动冲击、过载的跟腱负荷是造成下肢肌骨系统损伤的重要诱因。本项目针对拟解决的关键科学问题“如何通过跑姿控制减小着地冲击和改善跟腱力学特性”，在前期工作发现“主动改变着地姿态在减小冲击力、提高跟腱承受力中起到关键作用”的基础上，拟以“跑姿控制决定内/外在负荷”为项目主线，利用三维运动成像及测力系统、神经肌电信号结合肌肉建模仿真、跟腱超声影像与组织测量等方法，系统研究：①不同跑姿控制对着地冲击/冲击传递、软组织振动、跟腱载荷和下肢肌骨系统力学反馈的影响；②跑姿再训练干预模型对着地冲击生物力学、在体跟腱力学、材料特性/组织形态适应性的短、长期影响；③跑姿控制与再训练和神经肌肉疲劳对着地冲击力学和跟腱载荷生物力学的交互机制。以期进一步揭示人体运动控制模式与下肢外力冲击及足部内力载荷之间的调控规律和发生/发展机理，为实现从源头上认知和预防跑步冲击损伤、跟腱病提供新的理论和实践基础。

Repetitive passive impacts and the overload of Achilles tendon during running are two major risk factors for musculoskeletal injury in the lower extremity. This study aims to solve the key scientific problem of “how to reduce impact forces and improve the mechanical properties of Achilles tendon via running gait control”. Based on our previous findings of which “active changes in landing posture played a crucial role in reducing impact forces and improving the loading capability of Achilles tendon”, we intend to conduct a systematic study along with the main principle that “running gait control can determine the internal / external loading”. In this study, three-dimensional motion capture and force measurement system, neuromuscular electrical signals combined with muscle modeling and simulation, and Achilles tendon ultrasound imaging and tissue measurements were utilized. Specific aims: 1) to determine the effects of different gait control patterns on impact forces / impact transmission, soft tissue vibrations, Achilles tendon loading, and biomechanical feedback of the lower extremity during running; 2) to examine the short / long-term effects of running gait retraining on impact biomechanics, in vivo dynamic tendon mechanics, and tendon material properties / tissue adaptability; 3) to explore the interactive mechanism between gait control / retraining and neuromuscular fatigue on impact mechanics and Achilles tendon loading. These potential findings will reveal the insights and development mechanism of human motion control and external impact force of lower extremity & foot loading pattern, and further provide a new theoretical and practical basis for the comprehension and prevention of impact-related injuries / Achilles tendinopathy.