Background: Using wearable passive back-support exoskeletons in workplace has attracted attention as devices that support the posture of workers, enhance their physical capabilities, and reduce physical risk factors. Objects: This study aimed to investigate the effect of a wearable passive back-support exoskeleton on the activity of the erector spinae muscles during lifting tasks at various heights. Methods: Twenty healthy adult males were selected as subjects. Electromyography (EMG) was used to assess the activity of the erector spinae muscles while performing lifting tasks at three distinct heights (30, 40, and 50 cm), with and without the application of the Wearable Passive Back Support Exoskeleton. EMG data were gathered before and after the application of the orthosis. Results: The use of the Wearable Passive Back Support Exoskeleton resulted in a significant decrease in muscle activity when lifting a 10 kg object from heights of 30 and 40 cm (p < 0.05). Additionally, there was a significant reduction in muscle activity when lifting from a height of 50 cm compared with that at lower heights (p < 0.05). Conclusion: The use of a wearable passive back-support exoskeleton led to a decrease in the activity of the erector spinae muscles during lifting tasks, irrespective of the object's height. Our results suggest that the orthosis we tested may help decrease risk of lower back injuries during lifting.

INTRODUCTION
MATERIALS AND METHODS
    1. Participants
    2. Equipment
    3. Procedure
    4. Data Processing
RESULTS
    1. Change in MVIC According to the Wearable PassiveBack Support Exoskeleton at a Ground Height of 30cm
    2. Change in MVIC According to the Wearable PassiveBack Support Exoskeleton at a Ground Height of 40cm
    3. Change in MVIC According to the Wearable PassiveBack Support Exoskeleton at a Height of 50 cmFrom the Ground
DISCUSSION
REFERENCES

• Hee-Eun Ahn(Physical Therapy Section, Department of Rehabilitation Medicine, National Transportation Rehabilitation Hospital, Yangpyeong,)
• Tae-Lim Yoon(Department of Physical Therapy, College of Health and Medical Science, Cheongju University, Cheongju, Korea) Corresponding author