Ergonomic Workload, Musculoskeletal Symptoms, and Physiological Strain Among Juvenile Female Brickfield Workers: A Field-Based Analytical Cross-Sectional Study

Background: Juvenile (adolescent) girls from socio-economically disadvantaged households continue to perform heavy manual material-handling (MMH) tasks in India’s unorganized brick-manufacturing sector, despite legal protections against child labour. Evidence on their ergonomic exposures, physiological strain, and musculoskeletal health remains scarce. Objective: To evaluate the physical workload, postural stress, thermal exposure, musculoskeletal symptom prevalence, and acute physiological responses of juvenile girls employed in manual brick manufacturing units in West Bengal, India. Methods: A cross-sectional study design was adopted involving 100 young females within the age group of 13 to 18 years who worked at brick manufacturing plants in Nadia and Howrah districts of West Bengal. Data collection included interviews using modified Nordic questionnaires, anthropometry, activity observations both direct and video recorded, postural analysis through the Ovako Working Posture Analysis System (OWAS), thermal environment assessment, and physiological parameters both pre and post tasks of brick carrying. A paired t-test was performed to assess the physiological parameters before and after brick carrying, while the chi-square test was used to determine any relationship between musculoskeletal symptoms and BMI or the number of bricks handled per day. Results: The mean age was 15.5±2.33 years, BMI was 18.90±1.52 kg/m² and the occupational experience was 1.3±0.6 years. In general, 91% of participants complained of job-related pain, including the head (72%), neck (72%), and leg (78%). Neck pain was statistically correlated with chronic energy deficiencies (BMI < 18.5 kg/m², χ² = 9.675, p = 0.0019). Lifting more than 2,000 bricks per day was statistically correlated with head pain (χ² = 6.722, p = 0.0095), neck pain (χ² = 4.228, p = 0.0397), shoulder pain (χ² = 4.396, p = 0.0360), and back pain (χ² = 10.306, p = 0.0013). Bricks lifting led to a significant increase in heart rate (from 80.33±3.67 to 112.45±2.13 beats/min, p < 0.05), systolic blood pressure (from 119.7±3.5 to 134.9±5.15 mmHg, p < 0.05), and perceived exertion level (from 13.2±1.5 to 18.6±0.45). Participants performed 45% of the tasks moderately and 25% heavily; unloading bricks from the kiln top was the most dangerous according to the OWAS scale. Conclusion: Manual brick production entails heavy postural, thermal, and cardiovascular stress along with extremely high levels of musculoskeletal symptoms in female juveniles. There is an urgent need for intervention measures regarding ergonomics, nutrition, regulation, and education, including the abolition of hazardous juvenile labor, mechanization of load carrying, load restriction, rest breaks, hydration, safe postures, and schooling.