Kneeling seat is an ergonomic chair that can help the human body’s spine in a sitting posture to be closer to the natural state. In this study, we used non-contact camera method to measure visual distance. Using surface electromyography (sEMG) combined with subjective evaluation, we studied the obvious effects of seat angle and leg support angle in kneeling sitting posture on the ride comfort of healthy female school-age children without myopia. Using three experiment seat angles (10◦, 20◦ and 30◦), we found that as the sitting angle increased, the absolute value of the slope of the erector spinae linearity curve, MPF-t, gradually decreased. At 30◦, the slope of MPF-t was −0.26, the descent speed was the slowest, the activity of erector spinae was relatively lowest, and the comfort of children’s waist was also improved, while the comfort of calf gastrocnemius decreased, just the opposite. At the same time, leg support angles of 20◦, 30◦ and 40◦ were used. And in the study we found that the elevation of the leg support angle had no significant effect on the erector spinae muscle, but had a significant effect on the gastrocnemius muscle. When the leg support angle was 30◦, the slope of MPF-t was −0.42, and the gastrocnemius comfort reached its peak.
唐智1，鲍文岚1，陈晓燕1， 章蔚然1
,
刘佳沁1
,
王倩2
,
姜鑫玉1
. Comfort Kneeling Seat for School-Age Children[J]. Journal of Shanghai Jiaotong University(Science), 2024
, 29(6)
: 1009
-1016
.
DOI: 10.1007/s12204-022-2463-0
[1] HOU J J. Study on kneel-sitting comfort and design of new office chair [D]. Nanjing: Nanjing Forestry University, 2009 (in Chinese).
[2] BAO J H, DROBE B, WANG Y W, et al. Influence of near tasks on posture in myopic Chinese schoolchildren [J]. Optometry and Vision Science: Official Publication of the American Academy of Optometry, 2015, 92(8): 908-915.
[3] ZENG J, ZHU L S. Nordic modern furniture [M]. Beijing: China Light Industry Press, 2002 (in Chinese).
[4] BETTANY-SALTIKOV J, WARREN J, JOBSON M.Ergonomically designed kneeling chairs are they worth it? Comparison of sagittal lumbar curvature in two different seating postures [J]. Studies in Health Technology and Informatics, 2008, 140: 103-106.
[5] ALAMIN T F, AGARWAL V, ZAGEL A, et al. The effect of standing vs. variants of the seated position on lumbar intersegmental angulation and spacing: A radiographic study of 20 asymptomatic subjects [J].Journal of Spine Surgery, 2018, 4(3): 509-515.
[6] KONRAD P. The ABC of EMG: A practical introduction to kinesiological electromyography [M]. Scottsdale, USA: Noraxon Inc., 2005.
[7] SONG C, WANG D M, LU N Y. Changes of sEMG signals in lumbar muscles of women sitting in different postures [J]. Chinese Journal of Applied Physiology,2020, 36(1): 94-96 (in Chinese).
[8] LIU Z P. Effects of trunk rotation and backrest activity on lumbar sEMG activities, body pressure distribution and sitting discomfort during sitting [C]// 2019 6th
International Conference on Biomedical and Bioinformatics Engineering. Shanghai: ACM: 2019: 175-181.
[9] YU J H. Research on the comfort of the driving seat based on the body pressure [D]. Changsha: National University of Defense Technology, 2008 (in Chinese).
[10] YANG J. Study on the sofa back of the human comfort [D]. Nanjing: Nanjing Forestry University, 2008 (in Chinese).
