BIOMECHANICAL ANALYSIS OF SQUATTING IN OCCUPATIONAL TASKS WITH TWISTING

• Main Author: Utomo Soekarsono, Setyo
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79039
• Institution: Institut Teknologi Bandung

Squatting is an awkward working position that should ergonomically be avoided due to the high risk of work-related musculoskeletal disorders (WMSD). However, this working position is still prevalent in small and informal industries in Indonesia. There has been limited research on squatting with various biomechanical variables. This study investigated the squatting posture combined with twisting body movements using muscle fatigues as the indicator. The research was conducted through an experimental study in a laboratory setting using quantitative electromyography indicators and the qualitative Borg CR10 scale at left and right muscle of erector spinae, rectus femoris, and soleus. Eight young individuals accustomed to squatting in their daily activities were asked to simulate sorting work for 30 minutes, moving a 500-gram box from the left lateral position to the right lateral position with variations in angles of 30o and 60o . The findings revealed that in general there were no muscle fatigues but the right rectus femoris at a lateral angle of 30o indicated by significantly reduced MdF (p<0.05). Descriptively, an increase in twisting angle increased the workload on all muscles. However, this increase remained within acceptable limits. Additionally, the activities of the erector spinae and soleus muscles increased three to four times compared to squatting without twisting. Qualitative results showed that the highest discomfort was strong for soleus and somewhat strong for erector spinae and rectus femoris. The conclusion of this study is that 30 minutes of squatting work with twisting activities up to a 60o angle has the potential for WMSD higher in the erector spinae, rectus femoris, and soleus muscles compare with squatting work without twisting activities.. Although an increase in the twisting angle can increase the workload on these muscles, it still remains within acceptable limits.