Physical Support of Soldiers During CBRN Scenarios with Exoskeletons

The physical demands of overhead tasks can lead to musculoskeletal strain, particularly in scenarios requiring prolonged arm elevation such as in Chemical, Biological, Radiological, and Nuclear (CBRN) operations. To address this, an active shoulder exoskeleton was developed that is compatible with CBRN protective gear. The aim of this laboratory study was to assess the biomechanical and physiological effects of the system during upper limb tasks representative of real-world applications, without the use of protective suits. Twenty-two male participants performed two tasks with and without the exoskeleton: (1) 5 kg lifting task and (2) repetitive spraying tasks with a spray lance. Muscle activity of the m. anterior deltoid was measured using surface electromyography, while energy expenditure was assessed via spiroergometry. The exoskeleton significantly reduced muscular demands in the anterior deltoid, with a decrease of up to 40% during the spraying task and 29% percent during lifting task. Additionally, oxygen consumption per kilogram of body mass decreased by 6.5 to 8.2% across tasks. Participants reported lower fatigue and greater task manageability when using the exoskeleton, particularly for sustained and semi-static overhead postures. The results demonstrate that the exoskeleton effectively reduces workload during upper limb tasks. These findings support its application not only for soldiers in contaminated environments but also in industrial settings involving overhead work. Future research will need to validate these effects under realistic CBRN conditions to confirm operational compatibility.