A method for measuring the weight of human body segments based on 3D-printed body segments
Knowing human body segment weights is crucial in several applications. Alongside, there is a persistent need to present these segments in terms of their actual weight and morphology. Thus, this paper aims to construct customized 3D-printed models of some segments; the upper arm, forearm, hand, thigh, leg, and foot, then measure their weights using a digital scale. Sixty participants, both male and female, were recruited and assigned into experimental and control groups. The linear anthropometric measurements were taken for thirty individuals in the experimental group. The average of these measurements was used to adjust the ready 3D models of the stated segments. Then, the models were scaled and printed. Then, their weights were compared to the weight of every segment for each individual of the control group. The mean percent error of printed segments\' weight compared to the control group ranges between (8-9) %. Compared to the literature, the error range is acceptable. Hence, these printed models are a valid method to be used in several applications, including prosthetics manufacturing, car pedals\' design, garment design, etc.
Risk Assessment and Biomechanical Analysis of Sewing Machine operators using CATIA software
In garment factories, workers on sewing machines are under high risk of developing work related musculoskeletal disorders (WRMSDs). Therefore, this research aims to determine the prevalence of WRMSDs and perform a biomechanical analysis sewing machine workers postures to reduce the former risks. Two groups of workers were included, an experimental group, which includes 15 female sewing machine workers, and control group, which includes 10 females’ workers in administrative and supervisory jobs. The prevalence of MSDs was collected by
Standardized Nordic Questionnaire (SNQ) whereas a digital human model was built considering 50% percentile in CATIA software to perform Rapid Upper Limb Assessment (RULA) and single action biomechanical analysis. The results showed WRMSDs were more dominant in upper limb body segments of the experimental group. The RULA indicated that workers are under medium and high risks on the right and left parts of their body, respectively. More, the compressive force and joint shear on L4-L5 were within recommended limits however, the repetitive nature of job can make them risky. Findings of this work are of engineers and supervisors’ interest in garment factories to aid in evaluating risk factors that are leading to WRMSDS among their workers or other manufacturing field, hence modifying work area to be more ergonomic.