Comparison of the Effect of Ergonomics of Common School Benches on the Electrical Activity of Selected Muscles of Healthy Female Students or With Lumbar Lordosis

Background & objectives: Benches play a basic role in students sitting in the correct posture for a long period. The purpose of this study was to investigate the effect of ergonomics of common school benches on the electrical activity of selected muscles of healthy female students or with lumbar lordosis. Methods: For this purpose, 24 students with an average age of 10.26±1.78 years were selected and divided into two groups of 12 healthy subjects or with lordosis by convenience sampling. The students were sat down on two types of common benches in the school. At the beginning of sitting, a 30-second signal was taken from their selected muscles (rectus abdominis, spinal extensors, rectus femoris and biceps femoris), then a half-hour educational video was shown to them, and at the end, a 30-second signal was taken from their muscles. Statistical analysis of covariance was used to analyze the data. Results: There was a significant difference in the electrical activity of the muscles of healthy and lordosis students in attached benches in rectus femoris, biceps femoris and spinal extensors (p<0.001). There was no significant difference in rectus abdominis muscle (p<0.19). There was a significant difference in the electrical activity in the detached benches of the rectus femoris muscles (p<0.001). However, there was no significant difference in rectus abdominis (p<0.24), biceps (p<0.37) and spinal extensors (p<0.09). Conclusion: The results showed that sitting on attached benches was more inappropriate for students with lordosis. Therefore, it is recommended to design ergonomics standard table and benches based to the students' static anthropometric measurements.