STATIC SITTING POSTURE AMONG PRIMARY SCHOOL STUDENTS BETWEEN THREE TYPES OF SCHOOL CHAIR DESIGN USING ELECTROMYOGRAPHY (EMG) IN A PRIMARY SCHOOL IN BANTING, SELANGOR
DOI:
https://doi.org/10.37268/mjphm/vol.25/no.2/art.2554Keywords:
Ergonomic, ElectromyographyAbstract
Prolonged sitting in a static position, common in classrooms, can lead to discomfort around the lumbar area. The design of the seat is crucial when studying how people sit. This research analyses three types of primary school chairs: wood, plastic, and a combination of plastic and metal. Gathering quantitative data on how different seat depths affect individuals’ physiology is important. The study measured the activity of lumbar erector muscles (specifically, the trapezius and longissimus) using electromyography (EMG) in individuals who sat for extended periods in chairs with varying seat depths. EMG data were collected from 12 participants aged 7 to 12 in a primary school in Banting, Selangor. The study analysed muscle activity during static sitting and when participants were engaged in assigned tasks. The results showed that sitting statically with a bent posture was less comfortable than sitting with a leaning posture, as indicated by the trends and amplitude measurements. Specifically, the lowest root mean square (RMS) values, indicating comfort, were found in the leaning posture for the wooden chair (3.42E-05), mixed chair (1.52E-04), and upright posture (8.02E-05). Additionally, when slouching, the left trapezius muscle showed higher contractions than the right trapezius and the left and right longissimus muscles, with an RMS value of 2.00E+01. The last contracted muscle was the left longissimus muscle in the upright sitting posture, with an RMS value of 2.19E-06. In conclusion, the study examined three types of primary school chairs: wood, plastic, and a combination of plastic and iron. The findings revealed that prolonged sitting in a bent posture was less comfortable than sitting with a leaning posture. Moreover, higher muscle contractions were observed during slouching.
References
Khaltaev, N., Pfleger, B., Woolf, A., & others. (2003). “Assessing the burden of musculoskeletal conditions: A joint World Health Organization–Bone and Joint Decade project.” Arthritis Research & Therapy, 5(Suppl 3), 174
Adams, M., & Hutton, W. (1985). “The effect of posture on the lumbar spine.” The Journal of Bone & Joint Surgery British Volume, 67-B(4), 625-629.
Dankaerts, W., O'Sullivan, P., Burnett, A., & Straker, L. (2006). “Differences in sitting postures are associated with nonspecific chronic low back pain disorders when patients are subclassified.” Spine, 31(6), 698-704.
Roman-Liu, D., Tokarski, T., & Wójcik, K. (2004). “Quantitative assessment of upper limb muscle fatigue depending on the conditions of repetitive task load.” Journal of Electromyography and Kinesiology, 14(6), 671–682.
O’Sullivan, K., McCarthy, R., White, A., O’Sullivan, L., & Dankaerts, W. (2012). "The effectiveness of exercise therapy for patients with chronic low back pain: a systematic review and meta-analysis." Manual Therapy, 17(6), 566–571.
Leonard, J. H., Kok, K. S., Ayiesha, R., Das, S., Roslizawati, N., Vikram, M., & Baharudin, O. (2010). “Prolonged writing task: Comparison of electromyographic analysis of upper trapezius muscle in subjects with or without neck pain.” Clinica Terapeutica, 161, 29.
Testa, C. (2010). "Encyclopedia of Movement Disorders, Three-Volume Set." Elsevier.
Ernst, M. J., Rast, F. M., Bauer, C. M., Marcar, V. L., & Kool, J. (2013). "The effectiveness of a novel rehabilitation program for patients with chronic low back pain: A pilot study." BMC Research Notes, 6, 58.
Hashemirad, F., Talebian, S., Hatef, B., & Kahlaee, A. H. (2009). "Electromyographic assessment of lumbar muscle activity during various sitting postures." Journal of Electromyography and Kinesiology, 19(5), 746–753.
Carole, F., Ehrmann, F. D., Farida, C., & Hubert, L. (2011). “Clinical methods for quantifying body segment posture: A literature review.” Disability and Rehabilitation, 33(5), 367–383.
National Research Council, Division of Behavioral and Social Sciences, Board on Human-Systems Integration, Committee on Human Factors, Steering Committee for the Workshop on Work-Related Musculoskeletal Injuries, & The Research Base. (1998). Work-related musculoskeletal disorders: A review of the evidence. National Academies Press
Larson, D. J., & Brown, S. H. M. (2022). "Influence of back muscle fatigue on dynamic lumbar spine stability and coordination variability of the thorax-pelvis during repetitive flexion-extension movements." Journal of Biomechanics, 133
Castanharo, R., Duarte, M., & McGill, S. (2014). Corrective sitting strategies: An examination of muscle activity and spine loading. Journal of Electromyography and Kinesiology 24, 114–119.
Mandal, A. C. (1981). "The seated man (Homo Sedens): static muscular load and seating ergonomics." Applied Ergonomics, 12, 19–26.
Bischoff, S. C., Sellge, G., Lorentz, A., Sebald, W., Raab, R., & Manns, M. P. (1999). "IL-4 enhances proliferation and mediator release in mature human mast cells." Proceedings of the National Academy of Sciences of the United States of America, 96, 8080–8085.
Blanc, Y., & Dimanico, U. (2010). "Electrode Placement in Surface Electromyography (sEMG) 'Minimal Crosstalk Area' (MCA)." The Open Rehabilitation Journal, 3, 110–126.
De Luca, C.J. (1997). “The use of surface electromyography in biomechanics.” Journal of Applied Biomechanics 13, 135–163.
Garcia, M. A. C. & Vieira, T. M. M. (2011). “Surface electromyography: why, when and how to use it.” Rev Andal Med Deporte, 4:17-28.
Hermens, H.J., Freriks, B., Disselhorst-Klug, C., Rau, G., 2000. “Development of recommendations for SEMG sensors and sensor placement procedures.” J. Electromyogr. Kinesiol. 10, 361–374.
Ng, A., Hayes, M. J., & Polster, A. (2016). “Musculoskeletal disorders and working posture among dental and oral health students.” In Healthcare (Vol. 4, No. 1, p. 13). MDPI.
Grimes, P., & Legg, S. (2004). “Musculoskeletal disorders (MSD) in school students as a risk factor for adult MSD: a review of the multiple factors affecting posture, comfort and health in classroom environments.” Journal of the Human-Environment System, 7(1), 1-9.
Healy, G. N., Eakin, E. G., LaMontagne, A. D., Owen, N., Winkler, E. A., Wiesner, G., & Dunstan, D. W. (2013). “Reducing sitting time in office workers: short-term efficacy of a multicomponent intervention.” Preventive medicine, 57(1), 43-48.
Mesin, L., Cescon, C., Gazzoni, M., Merletti, R., Rainoldi, A. (2009). “A bi-dimensional index for the selective assessment of myoelectric manifestations of peripheral and central muscle fatigue.” J. Electromyogr. Kinesiol. 19, 851–863.
Afterman, M. M. (2019). “Ergonomics in Elementary School: A Multifaceted Approach for Laptop Computers in the Classroom.” In Proceedings of the Human Factors and Ergonomics Society Annual Meeting (Vol. 63, No. 1, pp. 868-872). Sage CA: Los Angeles, CA: SAGE Publications
