不同负荷模拟行走时的生理、生物力学信号分析

目的 分析不同负荷模拟行走过程中生理、生物力学信号及人体主观疲劳感的变化特征,探索导致负荷行走疲劳的相关因素.方法 选择6名健康成年男性进行5种负荷（25 kg,29 kg,34 kg,37kg,39 kg）模拟徒步行走试验（速度5 km/h,坡度0％）,连续行走30 min,同步采集心肺功能参数、肩部拉力、躯干压力、主观疲劳感等生理和生物力学信号.结果 随着负荷量增大,心率（heart rate,HR）、呼吸率（breathing rate,BR）、通气量（minute ventilation volume,VE）、摄氧量（oxygen consumption,V02）呈逐步上升趋势,且在37 ～39 kg段上升速率明显加快.肩部拉力与负荷量有较强的相关性.肩、背、腰部压力受背囊胸部束带、腰部束带的松紧程度影响较大,在37 kg处出现变化趋势转折点.肩和全身疲劳评分远高于背部和腰部.结论 37 kg是人体心肺功能疲劳的阈值点,在大于该负荷的行走试验中,应考虑受试个体的心肺运动能力对疲劳的影响.肩部拉力和压力可作为疲劳评价的主要因素.

Analysis of physiological and biomechanical signals during simulated walking with different loads

Objective To analyze the characteristics and trends of physiological and biomechanical signal and to explore relative factors resulting in fatigue in walking with load.Methods Cardio-pulmonary function parameters,shoulder force,trunk pressure,and perceived fatigue were sampled simultaneously in six healthy men during 30-minute simulated walking （speed at 5 km/h,slope at 0％） experiment under five different conditions of backpack loads （25 kg,29 kg,34 kg,37 kg,39 kg）.Results Heart rate （HR）,breathing rate （BR）,minute ventilation volume （VE）,oxygen consumption （VO2） gradually increased as the payload increased,and the increasing rate became bigger during 37-39 kg trials.Shoulder force was high correlated with payload.Pressures at shoulder,waist,and back regions were influenced by the tension degree of waist and chest belts,and 37 kg was the turning point.The scores of perceived fatigues in shoulder and whole body were higher than those of back and waist.Conclusions Thirty-seven kilogram is the threshold value of fatigue in cardio-pulmonary function,and cardio-pulmonary exercising capacity should be considered when we study simulated walking with payloads greater than 37 kg.Shoulder force and pressure are considered as main factors for fatigue evaluation.