Objective: To provide a comprehensive characterization of explosive ordnance disposal (EOD) personal protective equipment (PPE) by evaluating its effects on the human body, specifically the poses, tasks, and conditions under which EOD operations are performed. Background: EOD PPE is designed to protect technicians from a blast. The required features of protection make EOD PPE heavy, bulky, poorly ventilated, and difficult to maneuver in. It is not clear how the EOD PPE wearer physiologically adapts to maintain physical and cognitive performance during EOD operations. Method: Fourteen participants performed EOD operations including mobility and inspection tasks with and without EOD PPE. Physiological measurement and kinematic data recording were used to record human physiological responses and performance. Results: All physiological measures were significantly higher during the mobility and the inspection tasks when EOD PPE was worn. Participants spent significantly more time to complete the mobility tasks, whereas mixed results were found in the inspection tasks. Higher back muscle activations were seen in participants who performed object manipulation while wearing EOD PPE. Conclusion: EOD operations while wearing EOD PPE pose significant physical stress on the human body. The wearer’s mobility is impacted by EOD PPE, resulting in decreased speed and higher muscle activations. Application: The testing and evaluation methodology in this study can be used to benchmark future EOD PPE designs. Identifying hazards posed by EOD PPE lays the groundwork for developing mitigation plans, such as exoskeletons, to reduce physical and cognitive stress caused by EOD PPE on the wearers without compromising their operational performance.

[Purpose] This study was performed to examine the relationship between physical performance and muscle properties during police cadet training. The study's hypothesis was that improved physical performance brought about by training, would in turn cause a reduction in muscle flexibility. [Subjects and Methods] Fifty-nine police cadets were included in this study. Standard fitness tests and quantitative assessments of muscular biomechanical properties were conducted before, during and after the 20-week cadet training. [Results] General fitness had improved at the end of the police cadet training. There was no significant decrease in muscle flexibility as measured by the Sit-and-Reach test. However, muscle compliance of the non-dominant leg measured by the relaxation coefficient had decreased at the end of the police cadet training. [Conclusion] The increased sit-and-reach distance could be due in part to strengthening of the abdominal muscles. On the other hand, the biomechanical test, which was specific to muscle extensibility, showed a reduction in the relaxation coefficient of the non-dominant leg. Our data suggests that changes in muscle compliance as a result of lower extremity training should be considered. This data may be useful in the design of a training protocol that prevents the potential injuries caused by reduced muscle flexibility.

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