Pan Fumin, Wang Wei, Kong Chao, Lu Shibao
Department of Orthopedics, Xuanwu Hospital Capital Medical University, Beijing, China.
National Clinical Research Center for Geriatric Diseases, Beijing, China.
PeerJ. 2025 Jan 7;13:e18797. doi: 10.7717/peerj.18797. eCollection 2025.
Lifting is generally considered as a risk factor for low back pain. A thorough investigation of the muscle function during lifting is essential for a better assessment of the potential risk of muscle impairment and towards improvements in lifting strategy. We aimed to compare the activities of the trunk muscles between the stoop and the squat lifting tasks.
A surface electromyography device was used to measure the muscle activity during the full-cycle squat and the stoop lifting tasks of a 5-kg weight. Each task was divided into four stages: stage 1 was bending forward to reach the weight, stage 2 was lifting the weight up, stage 3 was lowering the weight down, and stage 4 was returning to the upright position. The maximum electromyographic (EMG) activities among different tasks and different stages were compared. Eighteen males aged 20-35 years without low back pain were included, with a mean age of 26.55 ± 2.12 years, body height of 175.18 ± 4.29 cm, body weight of 69.27 ± 4.29 kg, and BMI of 22.56 ± 0.87 kg/m.
During stoop lifting, the median values of the absolute EMG of the left multifidus were 53.96, 70.32, 51.08 and 64.14 uV from stage 1 to stage 4, which were all non-significantly lower than those during squat lifting for 79.84, 103.64, 71.72 and 95.72, respectively ( > 0.05). The absolute EMG was greatest during stage 2, then during stage 4, stages 1 and 3 came next (Effect size = 0.879, < 0.001). The median values of the normalized EMG of each muscle during stoop lifting were also non-significantly lower than those during squat lifting at each stage ( > 0.05). The normalized EMG was also greatest during stage 2, then during stage 4, and was lowest during stages 1 and 3 (Effect size = 0.932, < 0.001).
The trunk muscles were similarly activated during squat and stoop lifting. During lowering the weight down, the trunk muscles were less activated than during extension to the upright position without weight in hands. These results could help to develop subject-specific strategies for lifting tasks to prevent or alleviate occupational low back pain.
一般认为提举是下背痛的一个风险因素。深入研究提举过程中的肌肉功能对于更好地评估肌肉损伤的潜在风险以及改进提举策略至关重要。我们旨在比较弯腰提举和深蹲提举任务中躯干肌肉的活动情况。
使用表面肌电图设备测量在提起5千克重物的全周期深蹲和弯腰提举任务过程中的肌肉活动。每个任务分为四个阶段：阶段1为向前弯腰触及重物，阶段2为提起重物，阶段3为放下重物，阶段4为恢复到直立姿势。比较不同任务和不同阶段之间的最大肌电图（EMG）活动。纳入18名年龄在20 - 35岁之间无下背痛的男性，平均年龄为26.55±2.12岁，身高为175.18±4.29厘米，体重为69.27±4.29千克，体重指数为22.56±0.87千克/米²。
在弯腰提举过程中，从阶段1到阶段4，左侧多裂肌绝对EMG的中位数分别为53.96、70.32、51.08和64.14微伏，均显著低于深蹲提举过程中的相应值，分别为79.84、103.64、71.72和95.72（P>0.05）。绝对EMG在阶段2最大，然后是阶段4，阶段1和阶段3次之（效应量=0.879，P<0.001）。在弯腰提举过程中，各肌肉归一化EMG的中位数在每个阶段也均显著低于深蹲提举过程中的相应值（P>0.05）。归一化EMG同样在阶段2最大，然后是阶段4，在阶段1和阶段3最低（效应量=0.932，P<0.001）。
深蹲提举和弯腰提举过程中躯干肌肉的激活情况相似。在放下重物时，躯干肌肉的激活程度低于双手无重物伸展到直立姿势时。这些结果有助于制定针对个体的提举任务策略，以预防或减轻职业性下背痛。
