A wearable device for reducing spinal loads during lifting tasks: Biomechanics and design concepts

Manual material handling is one of the most frequent operations in industrial manufacturing processes. To avoid undesirable spinal loads, workers are often required to use external aid devices. This paper presents the analysis and design concept of a wearable assistive device for reducing the spinal loads during lifting tasks. A simplified model is used to compare the effects of two possible configurations for the device: the application of a force (a) parallel and (b) perpendicular to the spine. The model suggests that the perpendicular configuration (b) is preferable to (a). A subsequent numerical analysis suggests that the assistive device reduces substantially the spinal compression. This paper also discusses the design of a hardware prototype, that allows the operator to move mostly unhindered while performing lifting tasks. In particular the leg and torso movements on the sagittal plane are covered by the 90% and 60% respectively, while the movements on the frontal plane are fully covered.