Semi-quantitative ergonomic analysis of the biomechanical constraints within the cervical spine among screen-operators in the Tunisian universities

Abstract

Introduction: This study aims to evaluate the biomechanical constraints associated with neck pain among screen-operators. Methods: We conducted an ergonomic study of 325 screen-operators in 25 Tunisian universities based on an anthropometric evaluation of on-screen work and on a semi-quantitative analysis of video recordings of the activities of employees over a representative period of 30 minutes. Results: The prevalence of neck pain was 72.3% in a working population who had to seat in an unsuitable chair and to use an unsuitable worktop (84.6%) and a screen too low with regard to horizontal gaze (81.2%). A semi-quantitative analysis, using video recording of the workstation, concluded that the nape flexed more than 40 degrees for 69% of overall working time. Lateral flexion was observed for 50.3% of working time and right or left rotation for 57.4% of working time. Thus, the most limiting head posture on a postural and gestural level was observed when screen-operators read on a computer screen, had an incorrect positioning of the keyboard and consulted documents. Conclusion: Our results highlight the importance of biomechanical constraints associated with a design of on-screen work which is not in accordance with the ergonomically recommended anthropometric dimensions. These constraints are associated with a high prevalence of neck pain, reflecting the need to ensure an ergonomic design of workstations in order to prevent this problems.