Teo, Wei Peng

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.

Back pain and back-related injuries are common complaints among emergency responders. The purpose of this study was to compare the effectiveness of two strength and conditioning programs in improving back muscle characteristics and disabilities in emergency responders (firefighters/paramedics). Participants (n = 24) were randomized into two groups to complete 16 weeks of supervised exercise intervention: 1) Functional training used unilateral movements that mimicked the asymmetrical nature of emergency operations, 2) Conventional training performed bilaterally loaded exercises. Outcome measures were maximum isometric back extension strength, passive muscle stiffness, lumbar extensor fatigability, and revised Oswestry Low Back Pain Questionnaire. A mixed model Analysis of Variance with repeated measures was performed to compare the difference over time and between groups. While the training effects were similar between groups, both programs improved isometric back extension strength (+21.3% functional, +20.3% conventional, p < 0.001, ηp2 = 0.625) and lumbar extensor muscle fatigability (+17.4% functional, +9.5% conventional, p = 0.009, ηp2 = 0.191). Bilateral symmetry in muscle stiffness was improved as indicated by reduction in symmetry index (-7.1% functional, -11.8% conventional, p = 0.027, ηp2 = 0.151). All self-reported pain and disability scores fell within the category of “minimum functional limitation” throughout the intervention and 6-month follow-up periods. For frontline firefighters and paramedics, both functional and conventional strength training are effective for improving back muscle characteristics.