Biomechanical Constraints and Joint Load Among Healthcare Workers: Results from a Vector-Based Analysis in Real Work Situations

Background. Postural constraints are a major source of physical strain in caregiving activities, particularly in contexts characterized by high physical workload, lack of mechanical lifting aids, and poor ergonomic design. Given the high prevalence of musculoskeletal disorders (MSDs) among healthcare workers, an objective evaluation of biomechanical stress is essential. Objective. This study aimed to analyze joint biomechanical constraints associated with healthcare-related tasks using a dual approach: observational assessment with the Ovako Working Posture Analysis System (OWAS) and vector-based biomechanical modeling in real-world settings. Methods. A descriptive study was conducted across multiple hospital departments in the Wilaya of Batna. Working postures were assessed through direct observation and classified using the OWAS method. Biomechanical angular and vectorial analyses were performed on field photographs, using anatomical landmarks and body segment mass distribution based on De Leva’s method. Joint moments were calculated to estimate loading on critical joints, including the lumbar spine, shoulders, and knees. Results. OWAS analysis revealed a predominance of postures falling into Action Categories 3 and 4, indicating a need for urgent ergonomic intervention. The most hazardous postures involved trunk flexion, rotation, and prolonged static holding. Vectorial analysis confirmed significant lumbar loading, with joint stress values exceeding recommended safety thresholds—especially during patient handling and crouched cleaning tasks. Conclusion. Combining vector-based biomechanical analysis with systematic postural observation enables a comprehensive assessment of physical demands placed on healthcare workers. This integrated approach provides objective data to support preventive strategies, guide ergonomic workstation redesign, and reinforce training in safe working techniques. The findings underscore the urgent need for ergonomics-informed policies tailored to actual hospital working conditions.