Correlation between local musculoskeletal fatigue and WMSDs of workers in footwear industry

Objective To analyze the current status of work-related musculoskeletal disorders (WMSDs) and local musculoskeletal fatigue of workers in the footwear industry, and to explore the correlation among them.

Methods All workers from seven shoe-making enterprises in Fujian Province were surveyed using the stratified cluster sampling method from November 2018 to December 2019. The incidences of WMSDs, work fatigue, and musculoskeletal pain were investigated using the Chinese version of the Musculoskeletal Disorders Questionnaire, and correlation analysis was conducted.

Results Among the total of 4 139 workers, 3 565 valid questionnaires were collected. The overall incidence rate of WMSDs among shoemaking workers was 56.3%, mainly occurring in the neck (39.6%), shoulders (33.0%), hands/wrist (24.7%), lower back (21.5%), upper back (20.0%), ankle (14.2%), leg (13.2%), knee (11.9%), and elbow (10.7%). The pain score (VAS score) of musculoskeletal diseases in shoemakers regardless of location was (4.3 ± 1.6) points, and the pain degree was mild to moderate. Taking the rating of perceived exertion (RPE) score as the horizontal coordinate and the risk of WMSDs (OR value) corresponding to the score as the vertical coordinate, the model was fitted, and the results showed that the S-shaped function model fit better (R² = 0.872). With increasing RPE scores, the risk of WMSDs occurrence initially increased gradually, then sharply increased after an RPE score of 12, and finally leveled off. After adjusting for confounding factors such as gender and working time, the OR values (95% CI) for the risk of WMSDs in various body parts were: neck 9.597(8.168-11.275), shoulders 8.258(7.031-9.699), upper back 10.225(8.487-12.391), lower back 5.287(4.263-6.557), elbow 2.544(2.015-3.211), wrist/hand 10.432(8.753-12.433), leg 11.631(9.305-14.538), knee 10.770(8.450-13.728), ankle 14.589(11.683-18.218)(all P < 0.05). The attribution risk (AR) of musculoskeletal fatigue in various body parts ranged from 10.9% to 50.3%, with an attribution risk percentage (AR%) ranging from 55.6% to 86.0%. The correlation coefficients between work fatigue and pain scores by body parts, in order from highest to lowest, were for neck (0.532), ankle (0.512), shoulders (0.490), wrist/hand (0.487), upper back (0.461), leg (0.442), knee (0.433), lower back (0.328), and elbow (0.160)(all P < 0.05).

Conclusions There was a strong correlation between local musculoskeletal fatigue and WMSDs in shoemaking workers, which indicated that reducing fatigue levels is a significant preventive measure against WMSDs.