Abstract
Musculoskeletal injuries during the "Initial Training Phase" (ITP) are a major medical problem faced by law enforcement agencies worldwide. Aiming to develop an injury prevention strategy, we examined the incidence, type, associated factors, and severity of injuries and secondarily tracked their evolution over time by batches in a police academy. A retrospective cohort study was conducted using prospectively collected injury data on 979 newly recruited male police cadets enrolled in eight batches between 2015 and 2023. Among the 376 injured participants (age: 18.1 ± 0.3 years, body-mass: 75.8 ± 12.5 kg, body-height: 173.7 ± 4.0 cm, body mass index [BMI]: 25.1 ± 4.1 kg·m(-2), body-fat percentage: 18.1% ± 5.1%), 405 injuries were recorded during the ITP. Musculoskeletal injury data were analyzed according to type, associated-factors, severity, and evolution across batches. Almost half of the recruits (41.4%) sustained at least one musculoskeletal injury. Based on injury frequency (39-69 case) and exposure time (20,944.5-43,006.5 hours per participant) indices, and with an implication of scientific training tips, the long-term follow-up over-batches showed that the injury incidence was decreased 2.5-fold from Batch 1 to Batch 8 (p < .0001). Most injuries occurred between Weeks 2 and 5 (80% cumulative). The most common injury type was medial tibial stress syndrome (36.0%), followed by iliotibial band syndrome (12.6%), and ankle sprain (10.4%). This injury profile aligns with previous studies on law enforcement recruits, although comparisons should be made cautiously due to variations in training programs and recruit characteristics between agencies. The most frequently reported perceived potential contributors of injuries were vitamin and mineral deficiencies (20.7%), overweight/obesity (19.1%), and harsh physical activities (13.0%). During ITP, almost half of the recruits sustained at least one musculoskeletal injury, most of them in the fourth week. Some of the major associated factors of injury could be controlled resulting in a potential reduction of the injury incidence by up to 2.5 times. Implementing tailored fitness programs, incorporating subjective and objective training load assessments, and enhancing monitoring could significantly decrease injury rates, improve recruit readiness, and reduce resource and time waste on injury treatment.