Abstract:
This research aimed to design and construct of wood workbench utilizing ergonomic principles to reduce pain from workshop practices and to enhance vocational education efficiency of the first year students of Chiang Mai Technical College. According to the health survey, it was found that the students had low back pain symptom after continued using the workbench. Also, a questionnaire to evaluate abnormal index (AI) was used. The result indicated that the average value of AI value was 3.6. The Rapid Upper Limb Assessment (RULA) was also used to assess working posture of selected five students, the RULA point of 4 was found. Average EMG signals of left and right erector spinae were
11.9 mV and 11.7 mV, respectively. After analyzing, the low back pain was caused by mismatching of workbench height and students' anthropometric data, forcing students to bend their back over workbench while cutting, planning, screwing and assembling of wood works, especially, for continued usage over 6 hours. Then, the workbench was redesigned and constructed with better anthropometry match considering elbow height and forward grip reach. The new designed bench dimension was 75 x 150 x 9 6 em (width x length x height) attached with two vises placed on each side of the bench. After using the new bench for a few weeks the AI and RULA were assessed. It was found that the average AI was 2.7 or 33.33 percents reduction while the average RULA value .was decreased to 1. The EMG of the left and right erector spinae was also decreased to 9.5 mV and 9.7 mV or
19.9 percents and 17.6 3 percents reduction, respectively.