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Quantification of lower extremity physical exposures in various combinations of sit/stand time duration associated with sit-stand workstation

Huining Pei 1  ,  
Suihuai Yu 1,  
Jianjie Chu 1,  
Min Qu 1,  
Baozhen Tian 1,  
Northwestern Polytechnical University, Xi’an, China (Shaanxi Engineering Laboratory for Industrial Design)
Mississippi State University, Mississippi, USA (Department of Industrial and Systems Engineering)
Med Pr 2017;68(3):315–327
Background: Sit-stand workstations are available for office work purposes but there is a dearth of quantitative evidence to state benefits for lower limb outcomes while using them. And there are no guidelines on what constitutes appropriate sit/stand time duration. The primary aim of this study has been to compare muscle activity and perceived discomfort in the lower extremity during various combinations of sit/stand time duration associated with a sit-stand workstation separately and to evaluate the effects of the sit-stand workstation on the lower extremity during the text entry task. Material and Methods: During the 5 days, all participants completed a 2-h text entry task each day for various sit/stand time duration combinations as follows: 5/25 min, 10/20 min, 15/15 min, 20/10 min, 25/5 min. Lower extremity muscular exposure of 12 male and 13 female participants was collected at 8 sites by surface electromyography and body discomfort was calculated by a questionnaire under those 5 conditions. Results: Results have demonstrated that lower extremity muscle activity has been significantly varied among the 5 sit/stand time duration groups. Perceived level of discomfort (PLD) has not differed significantly for 9 out of 10 body parts. Conclusions: The muscle activity of the thigh region was influenced by sit/stand time duration significantly. Ergonomic exposures of lower extremity when using a sit-stand workstation were increased, particularly during the long time standing posture. Results indicate that body mass index (BMI) and gender were not significant factors in this study. Combination of sit/stand time duration 25/5 min appears to show positive effects on relief of muscle exposure of back of thigh in the shifts of sitting and standing work position. Med Pr 2017;68(3):315–327
Huining Pei   
Northwestern Polytechnical University, Shaanxi Engineering Laboratory for Industrial Design, West Youyi Road 127, 710072 Xi’an, China