Compressive loads on the lumbar spine during lifting: 4D WATBAK versus inverse dynamics calculations

Journal article

Cole, M. H. and Grimshaw, P. N.. (2005). Compressive loads on the lumbar spine during lifting: 4D WATBAK versus inverse dynamics calculations. Applied Bionics and Biomechanics. 2(3-4), pp. 149 - 160.
AuthorsCole, M. H. and Grimshaw, P. N.

Numerous two- and three-dimensional biomechanical models exist for the purpose of assessing the stresses placed on the lumbar spine during the performance of a manual material handling task. More recently, researchers have utilised their knowledge to develop specific computer-based models that can be applied in an occupational setting; an example of which is 4D WATBAK. The model used by 4D WATBAK bases its predications on static calculations and it is assumed that these static loads reasonably depict the actual dynamic loads acting on the lumbar spine. Consequently, it was the purpose of this research to assess the agreement between the static predictions made by 4D WATBAK and those from a comparable dynamic model. Six individuals were asked to perform a series of five lifting tasks, which ranged from lifting 2.5 kg to 22.5 kg and were designed to replicate the lifting component of the Work Capacity Assessment Test used within Australia. A single perpendicularly placed video camera was used to film each performance in the sagittal plane. The resultant two-dimensional kinematic data were input into the 4D WATBAK software and a dynamic biomechanical model to quantify the compression forces acting at the L4/L5 intervertebral joint. Results of this study indicated that as the mass of the load increased from 2.5 kg to 22.5 kg, the static compression forces calculated by 4D WATBAK became increasingly less than those calculated using the dynamic model (mean difference ranged from 22.0% for 2.5 kg to 42.9% for 22.5 kg). This study suggested that, for research purposes, a validated three-dimensional dynamic model should be employed when a task becomes complex and when a more accurate indication of spinal compression or shear force is required. Additionally, although it is clear that 4D WATBAK is particularly suited to industrial applications, it is suggested that the limitations of such modelling tools be carefully considered when task-risk and employee safety are concerned.

Keywordsspinal compression; lifting; manual material handling; 4D WATBAK; biomechanical model
JournalApplied Bionics and Biomechanics
Journal citation2 (3-4), pp. 149 - 160
PublisherHindawi Publishing Corporation
Digital Object Identifier (DOI)
Open accessOpen access
Page range149 - 160
Research GroupSports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre
Publisher's version
Additional information

Copyright © 2005 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Place of publicationUnited States of America
Permalink -

Download files

Publisher's version
  • 59
    total views
  • 98
    total downloads
  • 1
    views this month
  • 4
    downloads this month
These values are for the period from 19th October 2020, when this repository was created.

Export as