Effect of stool height on slumped posture during push-and-pull weeding motion

• Published in: Biomedical engineering letters Vol. 5; no. 2; pp. 79 - 86
• Main Authors: Cho, Young Kuen, Myeong, Seong-shik, Cho, Seungkwan, Kim, Han Sung
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Mechanical Engineers 01.06.2015; 대한의용생체공학회
• Subjects: Biological and Medical Physics; Biomechanics; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Engineering; Medical and Radiation Physics; Original Article; 의공학; Weeding; Stool height; Threedimensional motion analysis; Virtual human body model; Slumped posture
• ISSN: 2093-9868; 2093-985X
• DOI: 10.1007/s13534-015-0186-y

Purpose The excessive accumulation of work burden is one of the main factors underlying musculoskeletal disorders in the farming population. The present study was carried out to determine the joint torques and muscle contractions of the lower body in relation to slumped postures with or without a stool during push-and-pull weeding motions. Methods Using data from a 3D motion analysis system, a 3D virtual human body model was created consisting of 19 segments and 59 muscles. Among these, the lower body joints (ankle, knee, hip, and lumbar) and muscles (tibialis anterior, gastrocnemius, biceps femoris, and erector spinae) were analyzed for four cases of slumped postures: without a stool and with stools of various heights (10, 15, and 20 cm). Results The flexion of the lumbar joint was presented during push-and-pull weeding motions without a stool. However, the extension of the lumbar joint was presented during pushand-pull weeding motions with a stool. The ranges of the joint torques did not change in a meaningful way between the results for the cases without a stool and with a stool. In addition, the results according to the stool height did not present meaningful outcomes associated with the angle change in the joints. Conclusions Irrespective of the height, a stool may provide support for slumped postures involving the lumbar joint and erector spinae.