Fatigue state and external load effects on firefighter sprinting biomechanics

作者：Chuangui Mao, Ziwen Wang, Xinxin Zhang, Xiaoyi Ma, Sihang Zeng, Yunfei Hao, Weiguo Liu, Miao Yu · 发表于：Frontiers in Bioengineering and Biotechnology · 年份：2025 · DOI：10.3389/fbioe.2025.1677575 · 被引用次数：2 · 研究领域：Occupational Health and Performance、Sports Performance and Training、Lower Extremity Biomechanics and Pathologies

Objective This study investigates the biomechanical effects of fatigue and load on professional firefighters during sprinting, aiming to elucidate movement adaptations and injury risks under occupational rescue scenarios. We hypothesized that fatigue and load would independently impair sprinting performance and alter lower-limb biomechanics, leading to compensatory increases in joint moments and muscle activation. Methods Sixteen firefighters (23.13 ± 3.52 years) performed 20-m sprints carrying different loads (10–30 kg) in pre-/post-fatigue states. The statistical analysis was performed using SPSS and SPM1d for the two-way repeated-measures ANOVA. Results There were significant differences in the gait speed ( F = 14.019, p < 0.001, η 2 = 0.683), step length ( F = 30.512, p < 0.001, η 2 = 0.685), stance time ( F = 20.256, p < 0.001, η 2 = 0.591), rectus abdominis ( F = 6.757, p = 0.004, η 2 = 0.326), and rectus femoris ( F = 13.434, p = 0.002, η 2 = 0.490) under different load tasks. The results of SPM1d revealed significant differences in the hip flexion/extension angles ( F = 5.626, p = 0.049, 89.38%–99.30%), hip flexion/extension moments ( F = 9.981, p < 0.001, 92.16%–100%), and ankle dorsiflexion/plantar flexion moments ( F = 8.852, p = 0.003, 66.19%–78.98%) during the stance phase. Conclusion When sprinting with external weight constraints, gait metrics are negatively impacted, and compensating kinetic strategies increase push-off power from t...