Leg Swelling during Continuous Standing and Sitting Work without Restricting Leg Movement

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Leg Swelling during Continuous Standing and Sitting Work without Restricting Leg Movement: Akihiko SEO, et al. Department of Public Health, Hiroshima University School of Medicine-To clarify the dynamics of leg swelling during standing and sitting work without restricting leg movement, lower leg swelling and subjective complaints were measured during work under three working conditions: Straight standing, buttock chair sitting and ordinary chair sitting. Twelve subjects (eight males and four females) were assigned jigsaw puzzles as a task for an hour. The lower leg swelling and subjective complaints were recorded every two minutes. The lower leg swelling was measured by the bioelectrical impedance method. The results were as follows: (1) The lower leg swelling increased during the work under all working conditions. The swelling was least for straight standing and greatest for ordinary chair sitting. The mean and standard deviations for leg swelling after one hour''s work were 5.8±3.9% for straight standing, 8.2±4.7% for buttock chair sitting and 9.7±7.5% for ordinary chair sitting. (2) The subjective complaints also increased during work. Complaining of lower leg dullness was least for ordinary chair sitting and greatest for straight standing. The relation to the leg swelling was reversed. Complaining of low back pain was more common for buttock chair sitting than for other working postures. It is reasonable that prolonged standing is more likely to cause leg swelling than sitting because of high hydrostatic pressure. This theory has been supported by studies on motionless standing and sitting. Our results obtained without restricting leg movement, however, showed a reversed relation. It was considered that leg swelling factors such as low muscle activity and lymph pumps, low interstitial pressure brought on by low muscle activity, and the seat pressure during prolonged sitting may be dominant in the sitting posture although the hydrostatic pressure was low compared with the standing posture. (J Occup Health 1996; 38: 186-189)