Zhen Tao, Chen Qiuxia
National Defense Science and Technology Innovation Institute, PLA Academy of Military Sciences, Beijing, 100071, China.
School of Artificial Intelligence, Shenzhen Polytechnic University, Shenzhen, 518055, China.
Heliyon. 2024 Oct 2;10(19):e38912. doi: 10.1016/j.heliyon.2024.e38912. eCollection 2024 Oct 15.
Walking with heavy loads is a common task in military affairs and daily life. Considering that the shoulder and leg muscles fatigue will be caused during walking, which will affect the walking endurance and physical health. However, the suspended backpack is found to improve the energy efficiency of walking with a load. In this study, A lightweight suspended backpack is designed and proposing a model for estimating the metabolic cost of a suspended backpack based on gait phase. In this study, four inertial measurement units (IMUs) are fixed on the thigh and shank, six flexible pressure sensors are mounted on the soles of the feet and shoulders, respectively. The gait is defined as four successive phases. For each phase, the muscle tension is solved based on the muscle moment balance theory. Based on the phase segmentation method, the ECCF index is calculated by adding the gait phase constraint and backpack data calculation into the energy prediction model, and the relatively accurate data is obtained. In addition, In order to study the effects of the suspended backpack with different parameters on the cost metabolism, gait phase and biomechanics, the subjects need to carry the same load of 16.5 kg to walk 400 m at the different speeds, respectively. A group of seven healthy subjects in the same walking condition need to conduct two experiments: suspended backpack work (SB) and ordinary backpack (OB). The experimental results show that the suspended backpack can reduce plantar pressure and shoulder pressure in the SB condition. And at the speed of 5.0 km/h, ground reaction force (GRF) and shoulder reaction force (SRF) were reduced by 11.59 % and 13.22 % in the SB condition compared to the OB condition, respectively.
负重行走是军事活动和日常生活中的常见任务。考虑到行走过程中会导致肩部和腿部肌肉疲劳，这会影响行走耐力和身体健康。然而，人们发现背负式背包可以提高负重行走的能量效率。在本研究中，设计了一种轻质背负式背包，并提出了一种基于步态阶段估算背负式背包代谢成本的模型。在本研究中，四个惯性测量单元（IMU）固定在大腿和小腿上，六个柔性压力传感器分别安装在脚底和肩部。步态被定义为四个连续阶段。对于每个阶段，基于肌肉力矩平衡理论求解肌肉张力。基于相位分割方法，通过将步态阶段约束和背包数据计算添加到能量预测模型中来计算ECCF指数，并获得相对准确的数据。此外，为了研究不同参数的背负式背包对成本代谢、步态阶段和生物力学的影响，受试者需要分别以不同速度背负16.5千克的相同重量行走400米。一组七名健康受试者在相同行走条件下需要进行两项实验：背负式背包工作（SB）和普通背包（OB）。实验结果表明，在SB条件下，背负式背包可以降低足底压力和肩部压力。在5.0千米/小时的速度下，与OB条件相比，SB条件下的地面反作用力（GRF）和肩部反作用力（SRF）分别降低了11.59%和13.22%。
