Musculoskeletal Disorders and Biomechanical Constraints in a Tunisian Manufactory

Abstract

Introduction: Assessment risks of musculoskeletal disorders of the upper limbs (MSDs-UL) and their prevention requires a good identification of constraints to better loosen them and preserve the well-being of operators. Objectives: To quantify biomechanical risk factors of MSDs-UL among employees of an electronic industry in order to establish an appropriate preventive strategy. Materials and methods: This study is conducted in an assembly industry of electronic parts involving 85 women. This is a descriptive survey followed by an ergonomic intervention. Results: The middle age of the studied population was 35 years with an average of professional seniority of 14 years. In this company, 62% of workers are assigned at the assembly station, 26% at the control post and 12% at the welding position. The clinical examination concluded that 33% of workers had MSDs of the neck and upper extremity, of which 50% affected the wrist and the hand. MSDs mainly affect women over the age of 36 and having a professional seniority more than 11 years. The welding station was the most provider of MSDs. Repetitiveness and inadequate postures are the two commonly constraints reported by participants. However, the deployed force is described as weak. Observation analysis at the assembly station revealed a very high repetitiveness of postures in form of digital and lateral clamps. The weld station has been shown to have high repeatability with extreme wrist extension for 58% of the overall time and tightening during the entire work. At the checkpoint, the right wrist flexion for 43% of the time, the use of the hand as a hammer for 42% of the time and the shaping of grasp for 44% of the time are postural constraints performed with high repetition. Conclusion: The success of such prevention project must go beyond the medical framework to involve all partners in health and safety at work, especially the employer, operator and the ergonomist.