The effects of workplace intervention programs to manage work-related musculoskeletal pain among poultry slaughterhouse workers: A randomized controlled trial

Abstract

Background: The prevalence rate of work-related musculoskeletal pain (WMSP) among poultry slaughterhouse workers (PSW) has been reported in the shoulder, arm, and hand due to the involvement of repetitive and forceful upper limb movements. An intervention program is needed to reduce upper limb pain and improve upper limb functions among PSW. Objectives: This study aimed to investigate the effectiveness of workplace intervention programs on musculoskeletal pain, upper limb functions, and work ability among PSW. Materials and methods: A total of 48 participants (21 males and 27 females) who met the inclusion criteria were recruited into the study. The participants were allocated into two groups: The workplace intervention group (WIG, N=24; 10 males; 14 females) and the control group (CG, N=24; 11 males; 13 females). The WIG performed the exercise training with elastic resistance bands (ERB) and stretching exercises for eight weeks, and the CG did not perform any activity. The Visual Analogue Scale (VAS), shoulder reach flexibility test, active range of motion (AROM), the disability of the Arm, Shoulder, and Hand (KKU-DASH), and Thai Work Ability Index (Thai WAI) were used as outcome evaluations. The two-way analyses of variance (ANOVAs) with repeated measures (group x time) were used for statistical analyses, and the statistical significance was set at p<0.05. Results: Approximately 79.1% (N=19) of the participants in WIG reported significantly decreased pain intensity of upper limb 3.06 (0.83 to -5.4) in the right side (p<0.01) and 1.96 (1.6 to -5.6) in the left side (p<0.001) after the 8-week intervention. Meanwhile, shoulder flexibility in WIG significantly increased (p<0.001) to around 3.55 cm. (0.67 to 8.20) on the right side and 5.61 cm. (2.0 to 10.67) on the left side. For AROM in WIG, neck flexion, lateral neck flexion, neck rotation, and left shoulder flexion significantly increased (p<0.05), as well as KKU-DASH and Thai WAI scores (p<0.001). There was no significant difference within-group in all variables in CG. Conclusion: The workplace intervention program significantly reduced upper limb pain and increased neck movement and shoulder flexion among PSW. The training programs also improved work ability and reduced disability with upper extremity musculoskeletal conditions among PSW.