Handgrip strength asymmetry and occupational fitness in Korean coast guard officers: A cross-sectional study

Abstract

Handgrip strength (HGS) is a widely recognized indicator of muscular function and overall health. Beyond absolute values, grip strength asymmetry has recently been identified as a predictor of functional decline, fall risk, and occupational performance. However, little evidence exists regarding HGS in maritime law enforcement personnel, such as Coast Guard officers, whose duties demand balanced upper limb function for rescue, security, and operational tasks. This cross-sectional study included 120 active-duty Korean Coast Guard officers enrolled in a basic job training program. Hand dominance was determined by self-report, and maximum grip strength of both hands was assessed using a digital dynamometer. Asymmetry was calculated as the absolute difference between the two hands divided by the stronger hand, expressed as a percentage. Clinically meaningful asymmetry was defined as ≥10%. Analyses included paired t-tests, one-way ANOVA across age groups (20s, 30s, 40s, ≥50s), and independent t-tests by sex. Results: Mean dominant HGS was 44.7±4.9 kg, significantly higher than non-dominant HGS (44.1±4.7 kg, p < 0.001). Average asymmetry was 7.4±4.8%, and 25.8% of participants exceeded the 10% threshold. Officers in their 30s exhibited the highest absolute HGS, while those in their 20s showed the greatest asymmetry despite relatively high strength. Male officers had significantly greater absolute HGS than females (p < 0.001), while asymmetry did not differ by sex. Korean Coast Guard officers demonstrated significant dominance in HGS, with asymmetry most evident in younger officers. These findings suggest that occupational fitness programs should emphasize not only absolute strength but also bilateral balance, particularly among early-career personnel. This study provides initial evidence to support tailored fitness and injury prevention strategies for maritime law enforcement.