Repetitive overhead work with a heavy load increases the risk for work-related shoulder disorders. Occupational exoskeletons supporting arm elevation are potential solutions to reduce that risk by lowering the physical strains on the shoulder. Many studies have reported a reduction in shoulder stress in various overhead tasks by using such exoskeletons. However, the support demand can vary in each phase of motion as well as in each individual task. This paper presents a laboratory study with five participants to evaluate the influence of the support level of an active shoulder exoskeleton in different motion phases (e.g., arm lifting, screw-in, and arm lowering of two overhead tasks) to identify the potential optimization of support at each phase. Results show that the support level of the exoskeleton should be adapted to the motion phase of the two chosen tasks. A higher support force is desired for the screw phase compared to the arm lifting and lowering phases, and the support level needs to be reduced immediately for arm lowering after the screw phase. The time for switching the support levels can be recognized by the electric current of the screwdriver.

For patients suffering from drop foot due to weakness of ankle dorsiflexion muscles, an ankle foot orthosis provides increased foot clearance during the swing phase of gait, but often restricts other gait functions, such as plantarflexion. Due to steady progress in the development of lighter and smaller actuator technologies, active wearable devices such as exosuits become relevant for rehabilitation, since they can offer an extended functionality including a more comfortable wear than passive plastic orthosis. The aim of the paper is to present a lightweight exosuit supporting dorsiflexion during gait with autonomous recognition of gait phases and conditions. One main requirement during the iterative development of the exosuit is a non-restrictive function, thus no differences between the assisted and non-assisted gait of a healthy subject should occur. We therefore conducted a pilot biomechanics study using statistical parametric mapping to analyze kinematics of the ankle joint and muscle activity of m. tibialis anterior of nine subjects without any gait anomalies walking with and without the exosuit. The results show no significant difference between with and without support. In contrast to passive orthosis, the developed system could be an enhanced solution to assist patients suffering from drop foot, which should be analyzed in the next step for evaluating the development.

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.

Musculoskeletal disorders, particularly lower back pain, are common among healthcare workers due to frequent lifting, bending, and prolonged standing. To address this issue, we developed a lightweight, soft, and active exoskeleton designed to support lifting movements while maintaining user mobility and comfort. This paper presents the design of the exoskeleton. To assess the physiological effects on the wearer’s body, we conducted a biomechanical analysis, evaluating joint kinematics (hip and knee) and muscle activation (m. erector spinae and m. semitendinosus) during a lifting task. The results showed that the exoskeleton effectively reduced muscle activation in the m. erector spinae by 15.82 ± 13.35% and m. semitendinosus by 19.89 ± 20.84% without significantly altering the analyzed joint kinematics. These findings indicate that the system provides targeted support without restricting mobility, making it a promising tool for reducing physical strain in healthcare and other physically demanding professions.

Introduction: This study investigated the user experience and perceived acceptance of a shoulder exoskeleton during Chemical, Biological, Radiological, and Nuclear (CBRN) tasks in a military context. While laboratory research on the same system has shown measurable reductions in muscle activity of 29%–41%, the present field study focused on how end users subjectively evaluate the exoskeleton. Methods: Twenty-seven soldiers of the German Armed Forces tested the exoskeleton for approximately 30 min while completing standardized scenarios, including overhead lifting, vehicle decontamination with a spray lance, and casualty rescue. Immediately afterward, participants completed a structured questionnaire assessing usability, wearing comfort, impact on work routine, perceived support, usefulness, skepticism, and intention to use. Results: Overall, the exoskeleton was rated as easy to operate (mean item score: 5.15 ± 1.31 on a 7-point scale) and reasonably comfortable to wear (4.64 ± 1.31). Compatibility with work routines and perceived usefulness received moderate ratings (3.79 ± 1.53 and 3.05 ± 1.64, respectively), whereas the perceived mechanical support was notably low (2.78 ± 1.78). Skepticism (2.27 ± 1.08), and intentions to use the system were moderate (3.42 ± 2.08). Discussion: The user feedback suggests that while the current design is usable and generally comfortable, acceptance may improve substantially if future systems provide a higher amount of support and an expanded functionality to address a wider variety of tasks. These findings underscore that, beyond biomechanical effectiveness, user acceptance is a critical factor for the successful implementation of exoskeletons as occupational health interventions.