Exoskeleton robots promise to enhance safety by supporting workers' back strength during heavy lifting tasks, thereby improving work efficiency and productivity. However, the components of these robots, such as exoskeletal structures, actuators, and batteries, often increase their size and weight, which can reduce wearability and mobility. To tackle this issue, we propose a lightweight, passive wearable suit designed to assist back muscles during lifting tasks. The proposed system features a single elastic belt connected to multiple pulleys, which are attached to the back and lower limb sleeves. These pulleys are attached to the upper and lower limbs, and their relative distances change depending on body movements such as lifting or walking, thereby producing an effect similar to that of the moving pulley system. This innovative design allows the suit to deliver substantial support while efficiently distributing anchoring pressure across the wearer's skin during squatting and stooping positions. Additionally, the movement of belts through the pulleys minimizes the restrictions on gait motion compared to traditional designs. By adjusting the length of the belt, assist mode can be easily turned on and off, and flexibly applied to various body sizes. The supporting force is characterized by modeling and experimental tests. We evaluated the immediate effect of the prototype passively supporting back muscles during lifting tasks and reducing gait restriction during walking tasks.

Exoskeleton robots promise to enhance safety by supporting workers' back strength during heavy lifting tasks, thereby improving work efficiency and productivity. However, the components of these robots, such as exoskeletal structures, actuators, and batteries, often increase their size and weight, which can reduce wearability and mobility. To tackle this issue, we propose a lightweight, passive wearable suit designed to assist back muscles during lifting tasks. The proposed system features a single elastic belt connected to multiple pulleys, which are attached to the back and lower limb sleeves. These pulleys are attached to the upper and lower limbs, and their relative distances change depending on body movements such as lifting or walking, thereby producing an effect similar to that of the moving pulley system. This innovative design allows the suit to deliver substantial support while efficiently distributing anchoring pressure across the wearer's skin during squatting and stooping positions. Additionally, the movement of belts through the pulleys minimizes the restrictions on gait motion compared to traditional designs. By adjusting the length of the belt, assist mode can be easily turned on and off, and flexibly applied to various body sizes. The supporting force is characterized by modeling and experimental tests. We evaluated the immediate effect of the prototype passively supporting back muscles during lifting tasks and reducing gait restriction during walking tasks.

ObjectiveThe objective of the current study is to investigate how passive exoskeletons affect low-back passive tissues creep during prolonged stooping.BackgroundUsing exoskeletons could be a new strategy to prevent stress-relaxation deformation (creep) in low-back passive tissues induced by prolonged or repetitive stooping, but previous studies only focused on low-back active tissues.MethodTwelve healthy males completed 12 min of stooping (with and without a passive exoskeleton), while body kinematics and muscle activities were captured before and after stooping.ResultsResults indicate intact characteristics (i.e., no changes) in both active and passive tissues after enduring a 12-min stooping protocol while using the exoskeleton. However, without the exoskeleton, clear stress-relaxation deformation in low-back tissues, and changes in the load transfer mechanism between active and passive tissues after prolonged stooping, are observed, revealing a 3.19° delayed flexion-relaxation angle, a 5% maximum voluntary contraction increase in lumbar muscle activity, and a 2.8° increase in the maximum lumbar flexion angle.ConclusionThe supporting force provided by passive exoskeletons effectively limits stress-relaxation deformation in low-back passive tissues, such as ligaments, by preventing excessive elongation during prolonged stooping in a fully flexed posture, thereby reducing the possible risk of spinal instability and low back pain development.ApplicationThe study reveals the greater value of passive exoskeletons, which protect passive tissues in the low back. The research findings can serve as a valuable reference for practitioners in implementing effective countermeasures in the perspective of assistance devices to enhance occupational safety.

Additional contact points in sitting workstations (e.g., backrests, armrests) are advantageous by providing variable posture support, but no research has focused on increased contact points for standing workstations. This study investigated standing postural strategies and muscle recruitment characteristics for both pain developers (PDs) and non-pain developers (NPDs) when additional support was provided for the trunk and pelvis during prolonged standing at workstations. Sixteen participants each visited twice to test standing workstations (with and without the contact intervention) while subjective low back pain (LBP), movement patterns, movement variability, and muscle activation were monitored for 60 minutes. Results revealed that additional contact points reduced subjective LBP in PDs (47%) and triggered additional body movements (lumbar fidgeting: 38%; centre of pressure (CoP) shifting: 46%; and CoP fidgeting: 44%). In conclusion, improved postural stability throughout additional contact intervention encouraged alternate postures and thus decreased subjective LBP.