Low back pain and biomechanical characteristics of back muscles in firefighters

Abstract

Firefighters often experience low back pain (LBP), but their back muscle characteristics are not well studied. This study aimed to 1) compare the biomechanical characteristics of back muscles and self-reported back disabilities in frontline firefighters with and without LBP history, and 2) examine the relationships between back disability and biomechanical measurements. We recruited 42 male firefighters and assessed their perceived pain and disabilities, maximum isometric back extension strength, passive stiffness, and fatigability of the longissimus. 54.8% of the participants experienced LBP within the past year. Those indicating higher pain intensity also had greater disability as indicated by the Oswestry Disability Index. There were no significant differences in strength, stiffness or fatigability of the back muscles between firefighters with and without LBP history. Multiple linear regression analysis revealed no significant relationship between the back disability and any biomechanical or demographic measures, likely due to the high functional abilities of the participants.

Practitioner Summary

Approximately 50% of the firefighters who participated in the study experienced low back pain in the past 12 months. Since the pain level was mild to moderate, most of them continued to report to work. Biomechanically, there were no differences in back muscle strength, stiffness, resistance to fatigue, or left-right symmetry between firefighters with and without back pain history. Back disabilities were not related to any biomechanical measures or demographics including age and body mass index. Overall, despite experiencing some back pain, these frontline firefighters are highly functional and did not show diminished physical or neuromuscular responses.

Keywords:

• Back extension
• strength
• EMG
• stiffness
• emergency

Disclosure statement

Md Noor Hafiz Abd Halim and Hasan Kuddoos Abu Bakar Maricar were full-time employees hired under the Singapore Civil Defence Force (SCDF) which funded this research study. Other authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Data availability statement

The datasets generated for this study can be found in the NIE Data Repository [https://doi.org/10.25340/R4/S6LYLR].

Additional information

Funding

This study is supported by the Singapore Civil Defence Force (SCDF), Home Team Science and Technology Agency, Ministry of Home Affairs.