Profiling the injuries of law enforcement recruits during academy training: a retrospective cohort study

Prevalence and mechanisms of anterior cruciate ligament tears in military personnel: A cross-sectional study in Iran

BACKGROUND

Anterior cruciate ligament (ACL) tear is common in military setting; such an injury increase institutional costs and workforce strain, however, few studies have investigated the mechanism and associated factors of ACL tear specifically in a military setting. The aim of this study was to investigate the prevalence and mechanisms of ACL tears in military personnel at a military referral hospital in Iran.

MATERIAL AND METHODS

This cross-sectional study examined 402 military personnel who presented with knee complaints at a single referral Iranian military hospital. The ACL injury prevalence and mechanisms were assessed by physical examination, medical records, and magnetic resonance imaging (MRI) of the knee. Data were collected by an orthopedic resident.

RESULTS

Of the total 402 patients, 285 were diagnosed with ACL tears; the prevalence was 70.9%. The most common mechanism leading to ACL tear was noncontact events. The knee changing direction-knee pivoting (54%) was the most frequent lower limb status, followed by a fall with the knee in valgus position (20.7%). The most commonly associated activity was military training (63.9%) and sports activities (32.6%). The incidence of ACL injuries was higher in soldiers compared with officers during military training, but higher in officers during sports exercises (P = 0.002). Common associated injuries involved the knee meniscus and cartilage.

CONCLUSION

The findings support those of previous studies, that in military personnel, the most common knee injury is damage to the ACL, most frequently through noncontact events, specifically knee pivoting, during military activities rather than sports and among soldiers. These findings help develop ACL injury prevention programs.

Effects of a single-day pre-academy physical test training session on physical fitness scores of police candidates

BACKGROUND

Concerns are sometimes raised by police applicants undertaking physical fitness testing that they were unfamiliar with the test requirements which in turn negatively impacted their performance.

OBJECTIVE

The aim of this study was to investigate the effects of a single day physical test training session on physical fitness scores of police candidates.

METHODS

The sample consisted of female police candidates (n = 133) who attended a pre-academy training session. On the first day of pre-training, candidates' physical fitness was measured following official assessment day protocols. Measures included maximal handgrip strength, number of push-ups in 10 sec (PU), number of sit-ups in 30 sec (SU), standing long jump (SLJ), Abalakow jump test (AJ), 12 min Cooper running test (CT), and a motor educability test (ME). After the assessment, the overseeing UCIPS staff provided a detailed test skills briefing to candidates (e.g., common mistakes made during testing, how test performance could be improved, etc.). Immediately after the briefing, candidates performed the tests once again. Differences between results were measured using a paired samples t-test with significance set at 0.05.

RESULTS

Paired sample t-tests determined significant (p < 0.001), large (Rank-Biserial Correlation = 1.00), improvements in physical fitness scores during the second assessment following familiarisation and feedback on test performance.

CONCLUSION

Pre-academy training may be effective in improving candidates' physical fitness scores, in most tests, prior to the official assessment for the enrolment to police studies. Thus, to optimise initial candidate scores and opportunities for successful enlistment, police agencies may benefit from providing pre-assessment training.

Common law enforcement load carriage systems have limited acute effects on postural stability and muscle activity

Law enforcement officers are inherently at a high risk of injury and the loads they must carry during their occupational duties further increase their injury risk. It is unknown how different methods of carrying a law enforcement officer's load influence factors related to injury risk. This study assessed the effects of common law enforcement load carriage systems on muscular activity and postural stability while standing. Twenty-four participants performed single and dual-task (i.e. concurrent performance of cognitive tasks) standing while wearing a duty belt, tactical vest, and no load. The postural stability and muscle activity were measured and effects of condition and task examined. Dual task standing decreased postural stability and increased muscular activity. The belt and vest (7.2 kg each) increased muscle activity compared to control for the right abdominals, low back, right thigh. The duty belt resulted in less muscle activity in the right abdominals but more muscle activity in the left multifidus compared to the control. The findings indicate that common law enforcement load carriage systems increase muscular activity but do not affect postural stability. However, the lack of differences between the duty belt and tactical vest did not provide clear support for one load carriage system versus the other.

Effects of Law Enforcement Load Carriage Systems on Muscle Activity and Coordination during Walking: An Exploratory Study

Law enforcement officers (LEOs) commonly wear a duty belt (DB) or tactical vest (TV) and from prior findings, these forms of load carriage (LC) likely alter muscular activity. However, studies on the effects of LEO LC on muscular activity and coordination are limited in the current literature. The present study examined the effects of LEO load carriage on muscular activity and coordination. Twenty-four volunteers participated in the study (male = 13, age = 24.5 ± 6.0 years). Surface electromyography (sEMG) sensors were placed on the vastus lateralis, biceps femoris, multifidus, and lower rectus abdominus. Participants completed treadmill walking for two load carriage conditions (duty belt and tactical vest) and a control condition. Mean activity, sample entropy and Pearson correlation coefficients were computed for each muscle pair during the trials. The duty belt and tactical vest resulted in an increase in muscle activity in several muscles; however, no differences between the duty belt and tactical vest were found. Consistently across the conditions, the largest correlations were observed between the left and right multifidus (r = 0.33-0.68) and rectus abdominus muscles (0.34-0.55). There were statistically small effects (p < 0.05, η² = 0.031 to 0.076) of the LC on intermuscular coordination. No effect (p > 0.05) of the LC on sample entropy was found for any muscle. The findings indicate that LEO LC causes small differences in muscular activity and coordination during walking. Future research should incorporate heavier loads and longer durations.

Profiling the Typical Training Load of a Law Enforcement Recruit Class

Law enforcement academies, designed to prepare recruits for their prospective career, represent periods of high physical and mental stress, potentially contributing to recruits' injuries. Managing stress via monitoring training loads may mitigate injuries while ensuring adequate preparation. However, it is vital to first understand an academy's typical training load. The aim of this study was to profile the typical training load of law enforcement recruits over the course of 22 weeks. Data were prospectively collected using global positioning system (GPS) units placed on recruits during a portion of the academy training, while a desktop analysis was retrospectively applied to six other classes. A Bland-Altman plot was conducted to assess the agreement between the two methods. A linear mixed model was conducted to analyse the difference in distances covered per week, while other variables were presented graphically. Adequate agreement between the desktop analysis and GPS units was observed. Significant differences (p-value < 0.01) in distance covered (9.64 to 11.65 km) exist between weeks during early academy stages, which coincide with increases (~6 h) in physical training. Significant decreases in distances were experienced during the last five weeks of academy training. Most acute:chronic workload ratios stayed between the proposed 0.8 to 1.3 optimal range. Results from this study indicate that large increases in training occur early in the academy, potentially influencing injuries. Utilizing a desktop analysis is a pragmatic and reliable approach for instructors to measure load.