A Biomechanical Evaluation of Two Methods of Manual Load Lifting

Publisher Website
Google Scholar
Abstract
Since the middle 1930's it has been advocated that all lifting should be carried out with the back near vertical and with the knees bent. The basis for this recommendation has been that it shifts the stresses on the body from the low-back to the legs. Under certain conditions this recommendation is invalid. In this paper Chaffin and Baker's biomechanical lifting model is extended by considering the erector spinae muscles and by considering load accelerations. Mathematical modeling shows that forces on the erector spinae muscles and the lumbosacral disc can be as much as 50% higher when using the recommended “straight back, bent knees” method when compared to the common “stooped back” method. The straight back method is recommended only for lifts when the object is initially close to the spine.

This publication has 7 references indexed in Scilit: