(33) THE IMPACT OF RELATIVE STRENGTH ON SIMULATED FIRE-SUPPRESSION ACTIVITY PERFORMANCE TIMES

Abstract Details: Adequate muscular strength is important to the performance of fire-suppression activities. However, minimal evidence exists indicating an appropriate cut-off value for relative strength in firefighters. Insight into this area would help direct strength training programs for fire and rescue personnel.

Purpose: The purpose of the study was to determine how relative strength (RS) compared to performance on simulated fire suppression activities (sFSA).

Methods: 28 male career firefighters were recruited. Each firefighter performed the following timed (sec) sFSA as part of their annual physical abilities test: HD, search, rescue, forcible entry (FE), and LRE. In a subsequent test session, participants performed the isometric mid-thigh pull (IMTP). All firefighters were free of injury and not restricted from duty at the time of both testing sessions. The IMTP required participants complete 3 trials of a 5-sec isometric contraction using a custom strength testing device with an integrated load cell. The peak IMTP value was used to calculate RS (peak IMTP/body weight). Firefighters with an RS < 2.0x (n=12) were assigned to the weaker group, while firefighters with an RS ≥2.0x (n=16) were assigned to the stronger group. The inclusion criteria for each group were established based on the findings and recommendations of previous research. Multiple independent sample tests were used to analyze the difference between groups. As a result of a violation of normality in the FE measures, a Mann-Whitney U test was used to explore group differences for that variable. A Bonferroni correction to adjust the alpha level was used to mitigate the risk of a type 1 error when performing multiple statistical tests. The adjusted alpha level was set at .01.

Results: The analyzes revealed there were no statistically significant differences between groups for HD (13.6±3.1 vs 11.6±2.2, p=.05), search (40.2±8.3 vs 35.4±6.3, p=.09), rescue (15.6±3.3 vs 14.0±2.4, p=.157), FE (2.7±1 vs 2.6±1, p=.802), and LRE (27.3±2.9 vs 24.7±2.3, p=.02).

Conclusion: Although the performance times for the HD, search, rescue, and LRE were lower for the stronger group, they were not statistically significantly lower. PRACTICAL APPLICATION: The RS cut-off value of 2.0x a firefighter’s body mass may not be an adequate criterion for judging if a firefighter possesses sufficient muscular strength to quickly perform select FSA.

Acknowledgements:

Acknowledgments: The Oklahoma Center for the Advancement of Science and Technology (OCAST) grant number HR18-054. The results of the present study do not constitute an endorsement by the Oklahoma Center for the Advancement of Science and Technology.