无源被动负重型外骨骼对单兵满负荷行走运动的步态分析研究

Gait analysis of passive load exoskeleton on individual soldier's full-load walking

目的研究单兵使用无源被动负重型外骨骼(简称外骨骼)后对满负荷下行走的运动功能影响,为未来推广应用从而提升单兵负荷转运及改善该系统提供理论依据。方法试验中的无源被动式负重型外骨骼主要由绑缚带、背囊和背架、腰部组件、腿部组件等组成。招募14例男性志愿者,年龄24~37岁,平均年龄27.9岁(标准差3.17岁);身高169.0~185.0 cm,平均身高174.7 cm(标准差5.3 cm);体质量67.5~90.0 kg,平均体质量74.9 kg(标准差6.9 kg);身体质量指数22.6~27.9 kg/m^(2),平均身体质量指数24.5 kg/m^(2)(标准差1.6 kg/m^(2))。在穿戴外骨骼和背负25 kg背囊测试后,以问卷形式和三维红外捕捉步态分析检测,对工作效率、人体生理耐受、安全性、舒适性、移动灵活性、使用意愿和步态时空参数进行评分和量化评价。步态数据在Nexus V2.9软件中经三维建模,分析获得时空参数结果,并统计学分析各组数据。结果穿戴外骨骼可使负重行走时间平均缩短2.2 s,工作效率提高14.2%。穿戴外骨骼可使最大负重能力提高5kg。穿戴外骨骼将导致行走过程中膝关节最大活动角度平均丧失8°。有2例受试者发生了肩部皮肤轻微发红,没有发生重心不稳等安全事件的情况。使用无源被动负重型外骨骼后,测试者主观评估的舒适性(75.0±7.6)(60~90)分,移动灵活性(69.3±7.3)(60~80)分,使用意愿(72.1±7.0)(60~90)分。未穿戴外骨骼时,测试者背负25 kg后,步频、双足支撑时长、单足支撑时长和步速有显著性改变(P<0.05),而穿戴外骨骼后,测试者的步频、双足支撑时长、单足支撑时长和步速改变差异无统计学意义。结论单兵满负荷行走运动时,穿戴无源被动负重型外骨骼后可提高工作效率及最大负重能力,但会减小关节最大活动度,穿戴者仍自觉较高的舒适性和移动灵活性,愿意反复使用;步态分析证实,穿戴无源被动负重型外骨骼后,单兵满负荷行走运动功能可获得增强。

Objective To study the effect of passive load exoskeleton on motor function of individual soldiers in full-load walking, thus providing theoretical basis for future promotion application of the system, and improve the system for better full-load transfer of individual soldiers. Methods The passive load exoskeleton was mainly composed of straps, rucksack and back frame, waist components and leg components, etc. Fourteen male volunteers were recruited, which aged 24-37years old with mean age of 27.9 years old(standard deviation 3.17 years old);height was 169.0-185.0 cm with mean height of174.7 cm(standard deviation 5.3 cm);body mass was 67.5-90.0 kg with mean of 74.9 kg(standard deviation 6.9 kg);body mass index(BMI) was 22.6-27.9 kg/m^(2), with mean BMI of 24.5 kg/m^(2)(standard deviation 1.6 kg/m^(2)). After wearing exoskeleton and carrying 25 kg backpack assessment, the work efficiency, human physiological tolerance, safety, comfort, mobility flexibility, application intention and gait spatio-temporal parameters were scored and quantitatively evaluated by questionnaire and three-dimensional infrared capture gait analysis. The gait data was modeled in Nexus V2.9 software, and the results of spatiotemporal parameters were obtained and statistically analyzed. Results After wearing exoskeleton, the full-load walking time was shortened by 2.2 seconds on average, and work efficiency was increased by 14.2 %, the maximum full-load capacity was increased by 5 kg, and the maximum knee joint activity angle was lost by mean of 8° during walking. Two volunteers experienced slight redness of the shoulder skin, and without safety incidents such as unstable center of gravity occurred. After wearing passive load exoskeleton, the volunteers' subjective evaluation of comfort was(75.0 ± 7.6)(60-90) scores, mobility flexibility was(69.3 ±7.3)(60-80) scores, and application intention was(72.1 ± 7.0)(60-90) scores. When the exoskeleton non-worn, there were signifi cant changes in stride frequency, bipedal support duration, single foot support duration, and stride speed with the volunteers carry25 kg(P<0.05). There were no statistically significant differences in cadence, bipedal support time, single foot support time and stride speed after wearing the passive load exoskeleton. Conclusion It is demonstrated that after wearing passive load exoskeleton, individual soldiers walking in full-load still perceive high comfort and mobility, and willing to use it repeatedly. Gait analysis confirms that after wearing passive load exoskeleton, the individual soldier's full-load walking motor function can be enhanced.