Hierarchical Clustering Analysis of Musculoskeletal Stress Factors and Their Risk Level in Cardboard Manufacturing: A Research from PLIBEL.

OBJECTIVE: a hierarchical cluster analysis for the cardboard manufacturing industry was developed with the aim of identifying similarities between workstations in terms of musculoskeletal stress factors and their impact on workers' bodies.

METHODS: The hierarchical clustering analysis was conducted using data from 44 workstations, which included six body part divisions and 51 stress factors as variables with 36 answer options. Firstly, the content of the dataset was defined. Secondly, the data were agglomerated and classified into three clusters using Ward´s method based on the presence or absence of stress factors. Finally, the multivariable matrix was reduced to two factors: the x-axis represents the risk level of the workstation, and the y-axis represents the impact on the workers' health.

RESULTS: The study found that workers' knees were the most affected body parts, with 47 cases. The resulting work-related musculoskeletal disorders included tendinitis, arthralgia, chondromalacia, and gonarthrosis. The musculoskeletal stress factor with the most significant impact on the body's health was fatiguing work, which involves repeated jumps, prolonged squatting, or kneeling, present in cluster 1 and cluster 3. When the back is mildly flexed forward with one leg used more often in supporting the body, the repeated work position had the highest frequency of 63 and 56 answers.

CONCLUSIONS: It was possible to identify the main work-related musculoskeletal disorders and the associated stress factors for the cardboard manufacturing industry by utilising hierarchical cluster classification and analysis, enabling the classification of risk levels and the impact on body health for each workstation.