Predicting the load constant of the revised NIOSH lifting equation based on demographics

Manual materials handling (MMH) and lifting activities have been identified as risk factors for lower back pain (LBP). Of the many tools available to analyse and design lifting tasks, the revised NIOSH lifting equation (RNLE) is perhaps the most widely used. However, the equation is based on data primarily from the West. To make the model universally applicable, the effect of worker characteristics like age, gender, weight and anthropometry on maximum acceptable weight limits (MAWLs) was studied. A psychophysical methodology was adopted to arrive at the MAWLs. In total, 58 industrial workers (30 men and 28 women) participated in the study. Based on the observations of the study, an equation was developed that would allow the RNLE load constant to be modified for different populations based on simple anthropometric data. The load constant for the Indian population was found to be comparable to the RNLE recommendations.