Modelling Work Tasks and the Bending Capabilities of Subjects

The extent to which subjects can bend over while carrying out repetitive task, as measured by the postural angle, θ, in degree in relation to work space, without developing lower back pain (LBP) that is caused by over exertion of the thora-columbar force has been ascertained with the aid of anatomical model developed in this study. A free body diagram (FBD) of the human anatomical system was developed and used to carry out a biokinetic analysis in order to determine the theoretical relationship between the force erector muscle and the anthropometric variables. The model was fitted into anthropometric data of Nigeria population presented in percentile values. Our results suggest that the magnitude of erector muscle force is to a large extent determined by the body weight (WB) and trunk angle, θ. And that the reaction forces generated at the hip can be of the order of ten raised to power 3 of the body weight (WB). The utility of the research outcome appears appealing especially to Industrial Engineers who may find it needful for work space and jobs design.