Effectiveness of integrated ergonomics intervention approach in reducing musculoskeletal disorders among oil palm harvesters in Johor Bahru, Malaysia

This study intend to determine the effectiveness of an integrated ergonomics interventions approach, highly promoted by International Labour Organization to resolve ergonomics issues specifically among oil palm harvesters and to improve Occupational Safety and Health aspects of the workplace during early harvesting stage in oil palm plantation. Methodology: Divided into two phases, the first phase of the cross-sectional design involved 446 male respondents working as harvesters (263 fresh fruit bunch (FFB) cutters; 183 FFB collectors). Questionnaires were used to collect information on sociodemographic data, occupational history, social lifestyle, prevalence of musculoskeletal disorders (MSDs) and productivities data. Video recording was used to assist postural assessment of harvesters using Ovako Working Posture Analysis System (OWAS). An intervention package based on Participatory Action Oriented Training (PAOT) approach were subsequently designed and implemented in the second phase of the study. The intervention program features video, interactive lectures, games and action checklist. Two instruments were used to assess the effectiveness; knowledge, attitude and practice as well as body symptom questionnaire. Besides that, qualitative observation were also used to determine physical improvement or change from the intervention program. Results: Ergonomics risk factors particularly awkward postures, repetitive motion and forceful exertion were predominant among harvesters (both FFB cutters and FFB collectors) in oil palm plantation. Evidently, the 12 months and 7 days prevalence of MSDs at any body parts were 86% and 45% for respective duration. Lower back pain was the most commonly self-reported symptoms followed by knee neck and shoulder for both FFB cutters and FFB collectors. Significant risk factors of MSDs among the harvesters such as education level, body mass index, awkward postures, daily working and resting hours, working overtime and hobby (fishing) explain some but not all of the risk factors. Significant productivity loss were also observed among harvesters with acute MSDs where they were almost 3 times likely to be still working (presenteeism, OR=2.87; CI=1.34, 6.14) but produce only half as much as their healthy (without MSDs) colleagues (daily productivity, OR=2.09, CI=1.02, 4.29). The ergonomics intervention, PAOT approach were successfully implemented despite severely unanticipated and unavoidable limitations. The post-intervention assessment indicates that although the total knowledge, attitude and practices (KAP) score increased within IG (Friedman test, χ2=16.831, p