Estimation of Cumulative Compression Load on the L4/L5 Lumbar of Carpet Weavers through Direct Measurement of Trunk Posture and Direct Observation during a Shift Work

Epidemiological studies have shown a significant correlation between awkward back posture and low back pain among carpet weavers. Therefore, this study aims for estimating cumulative compression load among carpet weavers during a shift work. In this study, the awkward back postures of 4 male and 9 female carpet weavers were monitored, using electronic inclinometer for 4 hours. The level of cumulative compression load for a 8-hour shift was calculated. The highest compression load exerted on L4/L5 was due to the compacting and knotting subtasks. The maximum, cumulative compression load was related to the subtask of weaving. The levels of cumulative compression load during a shift work in male and female groups were estimated equal to 21.8 and 13.13MN-S, respectively. Results showed that although the level of compression load in both gender groups is lower than the recommended limit, the level of cumulative compression load in males is higher than in females. Therefore, results from different studies show that the estimation of compression load, per se, does not suggest the existence of physical stresses on the low back. In addition, the estimation of daily commutative compression can be an important index in predicting occupational low back pain