RESUMO
BACKGROUND: Physical overload at work has been described as a risk factor for the development of low back pain. However, few studies have investigated the prognostic value of perceived physical overload at work in patients with chronic low back pain. OBJECTIVE: To investigate the association of perceived physical overload at work with pain and disability over a period of 6 months in patients with chronic non-specific low back pain. METHODS: Patients with chronic LBP seeking physiotherapy care were considered eligible. Clinical data collected were: pain intensity, disability, fear of movement, depression and perceived physical overload at work. Linear regression analyses were used to investigate the association of perceived physical workload at work at baseline with pain intensity and disability at 6-month follow-up. The total score and the score for each category of the physical overload at work questionnaire were analyzed separately. RESULTS: Ninety-two patients with chronic low back pain were included in the analysis. The subcategories of the physical overload questionnaire were not significantly associated with pain intensity at 6-month follow-up. However, age, disability at baseline and perceived physical overload related to postures of the trunk (B = -0.60 95% CI - 1.18 to - 0.02) and related to positions of the arms (B = 2.72 95% CI 0.07 to 5.37) were significantly associated with disability at 6-month follow-up. CONCLUSION: Although perceived physical overload at work was not associated with pain intensity in patients with chronic LBP at 6-month follow-up, we identified a significant association between perceived physical overload related to postures of the trunk and positions of the arms with disability at 6-month follow-up. These slides can be retrieved under Electronic Supplementary Material.
Assuntos
Dor Crônica/etiologia , Dor Lombar/etiologia , Doenças Profissionais/etiologia , Estresse Fisiológico/fisiologia , Carga de Trabalho , Adulto , Dor Crônica/diagnóstico , Dor Crônica/fisiopatologia , Dor Crônica/psicologia , Avaliação da Deficiência , Feminino , Humanos , Estudos Longitudinais , Dor Lombar/diagnóstico , Dor Lombar/fisiopatologia , Dor Lombar/psicologia , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/diagnóstico , Doenças Profissionais/fisiopatologia , Doenças Profissionais/psicologia , Medição da Dor , Percepção , Exame Físico , Modalidades de Fisioterapia , Postura , Estudos Prospectivos , Fatores de Risco , Carga de Trabalho/psicologiaRESUMO
Although the workstations of a Brazilian automotive electrical harness production line are set close to TAKT time (the production rate required to meet demand), factory performance is compromised regarding: (i) sick leaves due to occupational disease (105 employees last year) and (ii) a production rate at only 42% of capacity. Our objective was to simulate the performance of a production line balanced against physical overload by the addition of an extra workstation. Based on ergonomic work analysis, the study applied System Dynamics at the global observation stage to obtain a systemic interpretation of the factors involved in production line performance. According to the indicators, the alternative configuration reduced physical overload by 36%, which would result in a sick leave rate of 50.8 employees/year (51.6% lower than the current configuration), as well as a production rate at 99% of capacity (a 92.7% increase over the current configuration). We found that reducing physical overload allows the "workforce control" loop to govern the system, producing favorable results. We conclude that setting the work cycle overly close to TAKT time leads to overload, due to the shorter recovery times at the end of each cycle. Thus, it is necessary to seek a balance between efficiency gains through downtime reduction and the physiological recovery of workers.