Technical-tactical behavior analysis of general duty police officers during non-compliant suspect apprehensions: A novel approach to establish minimum force requirements.

BACKGROUND: While effective apprehensions of non-compliant suspects are central to public safety, the minimal force needed to transition a suspect from standing to the ground, vital for apprehension success, has not been established. OBJECTIVE: To examine the technical-tactical behaviors of general duty police officers during simulated apprehensions and quantify the minimum force required to destabilize non-compliant suspects. METHODS: Task simulations conducted with 91 officers were analyzed to identify common grappling movements, strikes, control tactics, and changes in body posture. A separate assessment of 55 male officers aimed to determine the minimum force required for destabilization in five body regions (wrist, forearm, shoulder, mid-chest, and mid-back). Data are presented as mean±standard deviation. RESULTS: On average, apprehensions took 7.3±3.2 seconds. While all officers used grappling movements (100%) and the majority employed control tactics (75%), strikes were seldom used (4%). Apprehensions typically began with a two-handed pull (97%; Contact Phase), 55% then attempted an arm bar takedown, followed by a two-handed cross-body pull (68%; Transition/Control Phase), and a two-handed push to the ground (19%; Ground Phase). All officers began in the upright posture, with most shifting to squat (75%), kneel (58%), or bent (45%) postures to complete the apprehension. The minimum force required to disrupt balance differed across body regions (wrist: 54±12 kg; forearm: 49±12 kg; shoulder: 42±10 kg; mid-chest: 44±11 kg; mid-back: 30±7 kg, all P < 0.05), except between the shoulder and chest (P = 0.19). CONCLUSION: These findings provide insights that can enhance the design and accuracy of future apprehension evaluations and inform the optimization of law enforcement physical employment standards.

Physiological Demands of Basic Fire Management Tasks in Members of the Canadian Armed Forces: A Pilot Study.

INTRODUCTION: Members of the Canadian Armed Forces (CAF) are required to meet the minimum standards of the Fitness for Operational Requirements of CAF Employment (FORCE) job-based simulation test (JBST) and must possess the capacity to perform other common essential tasks. One of those tasks is to perform basic fire management tasks during fire emergencies to mitigate damage and reduce the risk of injuries and/or death until professional firefighters arrive at the scene. To date however, the physiological demands of common firefighting tasks have mostly been performed on professional firefighters, thus rendering the transferability of the demands to the general military population unclear. This pilot study aimed to quantify, for the first time, the physiological demands of basic fire management tasks in the military, to determine if they are reflected in the FORCE JBST minimum standard. We hypothesized that the physiological demands of basic fire management tasks within the CAF are below the physiological demands of the FORCE JBST minimum standard, and as such, be lower than the demands of professional firefighting. MATERIALS AND METHODS: To achieve this, 21 CAF members (8 females; 13 males; mean [SD] age: 33 [10] years; height: 174.5 [10.5] cm; weight: 85.4 [22.1] kg, estimated maximal oxygen uptake [$\dot V$O2peak]: 44.4 (7.4) mL kg-1 min-1) participated in a realistic, but physically demanding, JBST developed by CAF professional firefighting subject matter experts. The actions included lifting, carrying, and manipulating a 13-kg powder fire extinguisher and connecting, coupling, and dragging a 38-mm fire hose over 30 m. The rate of oxygen uptake ($\dot V$O2), heart rate, and percentage of heart rate reserve were measured continuously during two task simulation trials, which were interspersed by a recovery period. Rating of perceived exertion (6-no exertion; 20-maximal exertion) was measured upon completion of both task simulations. Peak $\dot V$O2 ($\dot V$O2peak) was estimated based on the results of the FORCE JBST. RESULTS: The mean (SD) duration of both task simulation trials was 3:39 (0:19) min:s, whereas the rest period in between both trials was 62 (19) minutes. The mean O2 was 21.1 (4.7) mL kg-1 min-1 across trials, which represented 52.1 (12.2) %$\dot V$O2peak and ∼81% of the FORCE JBST. This was paralleled by a mean heart rate of 136 (18) beats min-1, mean percentage of heart rate reserve of 61.2 (10.8), and mean rating of perceived exertion of 11 ± 2. Other physical components of the JBST consisted of lifting, carrying, and manipulating a 13-kg load for ∼59 seconds, which represents 65% of the load of the FORCE JBST. The external resistance of the fire hose drag portion increased up to 316 N, translating to a total of 6205 N over 30 m, which represents 96% of the drag force measured during the FORCE JBST. CONCLUSIONS: Our findings demonstrate that the physiological demands of basic fire management tasks in the CAF are of moderate intensity, which are reflected in the CAF physical fitness standard. As such, CAF members who achieve the minimum standard on the FORCE JBST are deemed capable of physically performing basic fire management tasks during fire emergencies.

Assessment of Training Load, Sleep, Injuries, and Operational Physical Performance During Basic Military Qualification.

INTRODUCTION: Optimizing training load (TL) and sleep is essential to maximize physical performance and prevent musculoskeletal injuries (MSKIs) for Canadian forces recruits during the 10-week basic military qualification (BMQ) course. The purpose of this study was to assess the TL, sleep duration, the occurrence of MSKIs during the BMQ, and the operation fitness performance during the BMQ. MATERIALS AND METHODS: Forty Canadian recruits, eight females and 32 males, (age 24 ± 5 years; height 176.4 ± 10.4 cm), were monitored with an accelerometer (GENEActiv) on their wrist between weeks 1 and 9 to evaluate the TL and sleep duration. During weeks 2 and 10, the recruits completed an operational fitness evaluation. Injury surveillance was performed over 10 weeks. RESULTS: TL intensity was significantly different (P = 0.0001) from week to week. The weekly average total time of moderate and vigorous physical activity was 189.7 ± 48.1 min and 44.7 ± 15.2 min, respectively. The average sleep duration was 5.4 ± 0.4 h per night and decreased to 4.2 h ± 0.4 during field exercises. A significant difference in sleep duration was observed between recruits with and without a MSKI. The recruits accumulated a total of 95 days under medical restrictions with an average of 3.8 consecutive days. The VO2peak estimated from the Fitness for Operational Requirements of Canadian Armed Forces Employment job-based simulation test significantly improved from weeks 2 to 10 (pre, 47.1 ± 6.3; post: 50.2 ± 5.8; P = 0.001). CONCLUSIONS: TL is of high magnitude and varies from week to week. The reported mean sleep duration per week may perhaps negatively impact the occurrence of MSKI. No significant improvement was detected in operational fitness by the end of the BMQ.

Explaining Performance on Military Tasks in the Canadian Armed Forces: The Importance of Morphological and Physical Fitness Characteristics.

Several occupations apply physical fitness tests to assess occupational physical performance to confirm that their employees meet minimum physical employment standards. Knowledge about factors affecting performance on these physical fitness tests could provide valuable information concerning mode of training. The main purpose of this study was to determine which morphological and/or physiological characteristics could explain overall performance outcome on six complex military tasks used to measure Canadian Armed Forces (CAF) members' occupational fitness. Measures of morphology (height, weight, and body composition) and physical fitness (grip strength, shuttle run time, and plank time etc.), together with performance on six common military tasks were recorded from female (n = 127) and male (n = 294) CAF members. Results showed large differences in both morphology and physical fitness between top and bottom performers in both the male and female group. Despite large differences in morphology, multiple linear regression analyses showed that measures of upper body strength and aerobic capacity could explain a large part of the performance variability in both the male and female group. This study showed that total performance on the CAF military physical fitness test is dependent on physical fitness rather than morphology.

Study on three-dimensional kinematics and electromyography of ACL deficient knee participants wearing a functional knee brace during running.

This investigation examined the muscular activity and 3D knee joint kinematic changes of anterior cruciate ligament-deficient (ACLD) participants in the involved leg under bracing condition during running. Different adaptation strategies have been found between patients who can cope with the injury and patients who cannot. One of the expected changes can be the muscle activation characteristic of the injured knee during strenuous activity with and without a functional knee brace. Three-dimensional kinematic and electromyographical (EMG) data were collected from 11 participants for 10 consecutive gait cycles during running on a treadmill under both braced and unbraced conditions. Participants were administered the "Knee Outcome Survey Activities of Daily Living Scale" to distinguish functional and non-functional candidates. No significant differences on 3D kinematics and EMG data were noted between functional and non-functional participants, thus data analysis focused on comparisons of bracing conditions for one combined group. Bracing significantly reduced total range of motion in the frontal and transverse planes (P<0.05). Muscle activity at heel-strike showed a consistent trend to increase for the hamstrings and decrease for the quadriceps under the braced condition when compared to the unbraced condition. Our findings indicate that bracing the ACLD knee alters the kinematics of the injured leg while running. Tendencies toward reductions in quadriceps and increases in hamstrings activity at heel-strike indicate that bracing might have resulted in added stability of the injured knee. The adaptations to bracing found in this preliminary study further support the potential mechanical and proprioceptive contributions of the functional knee brace to protect the ACLD knee.