Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Bioeng. Biotechnol.

Sec. Biomechanics

Volume 13 - 2025 | doi: 10.3389/fbioe.2025.1671642

This article is part of the Research TopicAdvancements in Running Biomechanics: Bridging Research and Practical ApplicationsView all 10 articles

Effects of External Load Magnitude and Carriage Techniques on Dynamic Stability and Work Performance during Fatigued Rescue Sprint Tasks in Firefighters

Provisionally accepted
Enmeng  JiangEnmeng Jiang1Yan  ShiYan Shi2Xinxin  ZhangXinxin Zhang2*Weiguo  LiuWeiguo Liu3*
  • 1School of Teacher Development, Shaanxi Normal University, Xi'an, China
  • 2Shaanxi Normal University School of Physical Education, Xi'an, China
  • 3College of Physical Education and Health, Guangxi Normal University, Guilin, China

The final, formatted version of the article will be published soon.

Background: This study aims to investigate the effects of different external load magnitudes and carrying techniques on dynamic stability and work performance during fatigued rescue sprint tasks in firefighters, thereby providing theoretical and practical support for injury prevention and performance enhancement in firefighting rescues. Methods: A total of 126 professional healthy male firefighters performed 30-meter rescue sprints under simulated fatigue in a 3 × 3 two-factor experimental design combining three external load magnitudes (10 kg, 20 kg, 30 kg) and three carrying techniques (shoulder-carry, bosom-carry, hand-carry). Results: External load magnitude had no significant effect on margin of stability in the medial and lateral directions (MoSml) (P > 0.05), but the margin of stability in the anterior and posterior directions (MoSap) was significantly lower under 10 kg load tasks compared to 20 and 30 kg loads (P < 0.05). The hand-carry technique significantly increased MoSap (P < 0.05) but significantly reduced MoSml (P < 0.05). For 20 kg loads, hand-carrying resulted in significantly increased MoSml compared to 10 and 30 kg tasks (P < 0.05), while bosom-carrying with 10 kg loads or shoulder-carrying with 20 kg loads significantly reduced MoSml (P < 0.05). Center of mass (CoM) work was significantly higher under 20 kg load tasks (P < 0.05). It was also significantly higher when using the hand-carry technique (P < 0.05), particularly when hand-carrying 20 kg loads (P < 0.05). Both external load magnitude and carrying technique significantly affected hip joint work (P < 0.05). Hip joint work was significantly higher under 10 kg loads (P < 0.05), and significantly greater when using hand-carrying compared to bosom-carrying (P < 0.05). Conclusion: It is recommended that firefighters choose carrying techniques based on specific load conditions: avoiding hand-carrying moderate loads, while shoulder carry for moderate to large loads, and bosom carry for small loads. Additionally, hip joint function training should be emphasised in daily

Keywords: Firefighter, External Load Magnitude, Carrying Technique, dynamic stability, Work performance

Received: 23 Jul 2025; Accepted: 09 Sep 2025.

Copyright: © 2025 Jiang, Shi, Zhang and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Xinxin Zhang, Shaanxi Normal University School of Physical Education, Xi'an, China
Weiguo Liu, College of Physical Education and Health, Guangxi Normal University, Guilin, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.