Can Lower-Body Strength and Power Alleviate Load Carriage Performance Decrements (Tactical Deficit) in Simulated Law Enforcement Job Tasks?

Abstract

Law enforcement agencies typically have recruits complete fitness assessments without personal protective equipment (PPE). PPE negatively impacts performance. Greater strength and power could alleviate performance decrements due to the extra load, termed the tactical deficit (TD). The purpose of this study was to examine whether lower-body strength or power related to the TD in civilians performing police tasks. Twenty participants (12 men, 8 women) completed baseline tests, including: standing broad jump (SBJ); relative SBJ; absolute and relative isometric leg/back dynamometer (LBD) and one-repetition maximum hexagonal bar deadlift (HBD). In two other sessions, participants completed four police tasks, either unloaded or loaded (PPE=~8-10 kg), in a counterbalanced order: vertical jump (VJ), 75-yard pursuit run (75PR), 74.84-kg body drag, and 500-yard run. The VJ was also used as a power metric, with peak anaerobic power and power:body mass (P:BM) derived. Paired samples t-tests investigated differences between unloaded/loaded conditions for each task for each sex. Independent samples t-tests compared the sexes. Pearson's correlations derived relationships between strength and power tests with each task TD for each sex. Load negatively impacted task performance (p≤0.011); males generally outperformed females (p≤0.044). Superior SBJ, relative SBJ, VJ, P:BM, and absolute and relative HBD related to a smaller 75PR TD (r=-0.582 to -0.838). Greater absolute and relative HBD related to a lower body drag TD (r=-0.576 to -0.618) in men. For women, the relative SBJ related to a smaller VJ TD (r=-0.727). Developing lower-body strength and power could offset TD in foot pursuit and dragging tasks for personnel.