Tianjin University of Science and Technology
目的 研究老年人在手部不同负重分布条件下跨越障碍物时，导致跌倒风险性增加的因素，并得出预防老年人在负重跨障时跌倒的步态策略。方法 12名老年人和12名青年人（对照组）以日常行走步速在不同负重分布方式下进行跨越障碍物和无障碍物行走任务，采集股外侧肌、股直肌和股内侧肌双侧的表面肌电信号，然后进行平均肌电值分析对比，同时记录受试者跨越障碍时触碰障碍物的情况。结果 年龄因素、负重因素及跨障因素均对老年人下肢肌肉的活动水平产生了显著影响。1152次跨障试验中共发生9次触障事件。另外，老年人和青年人在完成负重和跨障任务时RVM的肌肉贡献量最大。结论 通过VL、RF和VM的肌肉活动水平和触障事件统计结果表明老年人在负重物均匀分布下利用腿部优势侧率先跨障的情况下跌倒的风险性最低。本研究为系统评估老年人跌倒风险提供参考，对老年人针对性下肢运动锻炼或康复训练有一定的指导意义。
Objective The purpose of the study was to investigate the effects of different load distributions on lower limb muscle activity in the older groups during obstacle crossing. Method 12 young healthy (control group) and 12 senior healthy participants performed walking tasks including obstacle crossing and walk straight at their daily pace carrying different weight distributions (no weight, weight a 5kg dumbbell in one hand and weight 2.5kg dumbbell in both hand). Surface Electromyography (sEMG) signals were collected from both sides of the lateral femoris, rectus femoris and medial femoris. Then the average of sEMG was analyzed and compared. The participants' touching of obstacles while crossing the obstacles were also recorded. Results indicated that crossing obstacles and different weight distribution patterns had significant effects on the lower limb muscle activity level of the elderly group. Result Age, weight carrying and obstacle all have significant influence on the activity level of lower limb muscles. A total of 9 contact incidents occurred in 1152 obstacle crossing tests. In addition, the RVM muscle contribution was greatest in the elderly and young adults when they completed weight carrying and obstacle crossing tasks. Conclusion According to the statistical results of muscle activity level and touch event of VL, RF and VM, the elderly had the lowest risk of falling down in the condition of taking advantage of the dominant side of the leg to take the lead in crossing the obstacle under the uniform distribution of load. This study provides a reference for the systematic assessment of the risk of falls in the elderly and has certain guiding significance for targeted lower limb exercise or rehabilitation training in the elderly.