Quantification of lower extremity physical exposuresin various combinations of sit/stand time durationassociated with sit-stand workstation

摘要

Background: Sit-stand workstations are available for office work purposes but there is a dearth of quantitative evidence to statebenefits for lower limb outcomes while using them. And there are no guidelines on what constitutes appropriate sit/stand timeduration. The primary aim of this study has been to compare muscle activity and perceived discomfort in the lower extremity duringvarious combinations of sit/stand time duration associated with a sit-stand workstation separately and to evaluate the effects ofthe sit-stand workstation on the lower extremity during the text entry task. Material and Methods: During the 5 days, all participantscompleted 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 sitesby surface electromyography and body discomfort was calculated by a questionnaire under those 5 conditions. Results: Resultshave 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 ofthe thigh region was influenced by sit/stand time duration significantly. Ergonomic exposures of lower extremity when usinga 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 showpositive 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