The Difference In Fitness And Lower Body Power Based On Mobility Status In First Responders

First responders have physically demanding jobs with an increased risk of injury. Previous research has shown that asymmetry of mobility and stability in the lower extremity is associated with an increased risk of lower extremity injuries, while increased fitness and lower body power are associated with a reduced risk of injury. However, there is limited research examining the relationship between lower limb asymmetry, fitness and lower body power output in first responders. PURPOSE: Examine differences in fitness and lower body power output of individuals above and below the acceptable threshold for the anterior reach Y-Balance Test (ANT YBT) in first responders. METHODS: Thirty-two male first responders (Age = 42.09 ± 10.587 years; Body Mass Index = 29.6 ± 3.8 kg/m2) participated in a fitness assessment including measures of cardiorespiratory endurance, body composition, flexibility, and muscular strength and endurance. Subjects also completed the ANT YBT to assess lower limb mobility and stability and a countermovement jump using force plates to assess lower body power. The subjects were grouped based on their ANT YBT performance (Asymmetry is defined as a difference between right and left leg performance greater than the acceptable limit of 4 cm). Independent t-tests were utilized to examine differences between the groups for all fitness variables and measures of lower body power and velocity from the force plate output. RESULTS: Statistically significant differences were identified for Hand Grip Strength (HG) (t29 = 2.219, p = 0.034), Average Propulsive Power (APP) (t29 = -2.487, p = 0.019), and Average Propulsive Velocity (APV) (t29 = -2.500, p = 0.018), with individuals in the asymmetry group. Those with asymmetries had higher APP (2311.57 ± 363.32 W), APV (1.47 ± 0.15 m/s), and HG (113.01 ± 13.42 kg) compared to individuals with asymmetries within the acceptable limit. CONCLUSIONS: The results indicate that first responders with lower body mobility and stability asymmetries produce more force and power. Previous research suggests that asymmetries increase risk of injury, however, it does not examine the interaction of strength and asymmetry and its impact on potential injury. Future research may examine how high fitness levels accompanied by asymmetries may further increase the risk of lower extremity injury.